package net.i2p.data.i2np;
/*
* free (adj.): unencumbered; not under the control of others
* Written by jrandom in 2003 and released into the public domain
* with no warranty of any kind, either expressed or implied.
* It probably won't make your computer catch on fire, or eat
* your children, but it might. Use at your own risk.
*
*/
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import net.i2p.I2PAppContext;
import net.i2p.data.DataHelper;
import net.i2p.data.Hash;
import net.i2p.data.router.RouterInfo;
import net.i2p.data.SessionKey;
import net.i2p.data.SessionTag;
import net.i2p.data.TunnelId;
//import net.i2p.util.Log;
import net.i2p.util.VersionComparator;
/**
* Defines the message a router sends to another router to search for a
* key in the network database.
*
* @author jrandom
*/
public class DatabaseLookupMessage extends FastI2NPMessageImpl {
//private final static Log _log = new Log(DatabaseLookupMessage.class);
public final static int MESSAGE_TYPE = 2;
private Hash _key;
private Hash _fromHash;
private TunnelId _replyTunnel;
/** this must be kept as a list to preserve the order and not break the checksum */
private List<Hash> _dontIncludePeers;
private SessionKey _replyKey;
private SessionTag _replyTag;
private Type _type;
//private static volatile long _currentLookupPeriod = 0;
//private static volatile int _currentLookupCount = 0;
// if we try to send over 20 netDb lookups in 10 seconds, we're acting up
//private static final long LOOKUP_THROTTLE_PERIOD = 10*1000;
//private static final long LOOKUP_THROTTLE_MAX = 50;
/** Insanely big. Not much more than 1500 will fit in a message.
Have to prevent a huge alloc on rcv of a malicious msg though */
private static final int MAX_NUM_PEERS = 512;
private static final byte FLAG_TUNNEL = 0x01;
// any flags below here will confuse routers 0.9.5 or lower
private static final byte FLAG_ENCRYPT = 0x02;
private static final byte FLAG_TYPE_MASK = 0x0c;
private static final byte FLAG_TYPE_ANY = 0;
private static final byte FLAG_TYPE_LS = 0x04;
private static final byte FLAG_TYPE_RI = 0x08;
private static final byte FLAG_TYPE_EXPL = 0x0c;
/** @since 0.9.16 */
public enum Type {
/** default - LS or RI */
ANY,
/** lease set only */
LS,
/** router info only */
RI,
/** exploratory - return closest non-floodfill router infos */
EXPL
}
/**
* It's not supported until 0.9.7, but as of
* 0.9.6 we can specify the bit in the flags without
* the receiver rejecting the whole message as invalid.
*/
private static final String MIN_ENCRYPTION_VERSION = "0.9.7";
public DatabaseLookupMessage(I2PAppContext context) {
this(context, false);
}
/** @param locallyCreated ignored */
public DatabaseLookupMessage(I2PAppContext context, boolean locallyCreated) {
super(context);
//setSearchKey(null);
//setFrom(null);
//setDontIncludePeers(null);
// This is the wrong place for this, any throttling should be in netdb
// And it doesnt throttle anyway (that would have to be in netdb), it just increments a stat
//context.statManager().createRateStat("router.throttleNetDbDoSSend", "How many netDb lookup messages we are sending during a period with a DoS detected", "Throttle", new long[] { 60*1000, 10*60*1000, 60*60*1000, 24*60*60*1000 });
//
// only check DoS generation if we are creating the message...
//if (locallyCreated) {
// // we do this in the writeMessage so we know that we have all the data
// int dosCount = detectDoS(context);
// if (dosCount > 0) {
// if (_log.shouldLog(Log.WARN))
// _log.warn("Are we flooding the network with NetDb messages? (" + dosCount
// + " messages so far)", new Exception("Flood cause"));
// }
//}
_type = Type.ANY;
}
/**
* Return number of netDb messages in this period, if flood, else 0
*
*/
/*****
private static int detectDoS(I2PAppContext context) {
int count = _currentLookupCount++;
// now lets check for DoS
long now = context.clock().now();
if (_currentLookupPeriod + LOOKUP_THROTTLE_PERIOD > now) {
// same period, check for DoS
if (count >= LOOKUP_THROTTLE_MAX) {
context.statManager().addRateData("router.throttleNetDbDoSSend", count, 0);
return count;
} else {
// no DoS, at least, not yet
return 0;
}
} else {
// on to the next period, reset counter, no DoS
// (no, I'm not worried about concurrency here)
_currentLookupPeriod = now;
_currentLookupCount = 1;
return 0;
}
}
*****/
/**
* Defines the key being searched for
*/
public Hash getSearchKey() { return _key; }
/**
* @throws IllegalStateException if key previously set, to protect saved checksum
*/
public void setSearchKey(Hash key) {
if (_key != null)
throw new IllegalStateException();
_key = key;
}
/**
* Defines the type of data being searched for.
* Default ANY.
*
* @return non-null
* @since 0.9.16
*/
public Type getSearchType() { return _type; }
/**
* Defines the type of data being searched for.
* Default ANY.
* Must be ANY for queried routers 0.9.5 or lower, but there are few if
* any floodfills that old left, so not even worth checking.
*
* @param type non-null
* @since 0.9.16
*/
public void setSearchType(Type type) {
if (type == null)
throw new IllegalArgumentException();
_type = type;
}
/**
* Contains the router who requested this lookup
*
*/
public Hash getFrom() { return _fromHash; }
/**
* @throws IllegalStateException if from previously set, to protect saved checksum
*/
public void setFrom(Hash from) {
if (_fromHash != null)
throw new IllegalStateException();
_fromHash = from;
}
/**
* Contains the tunnel ID a reply should be sent to
*
*/
public TunnelId getReplyTunnel() { return _replyTunnel; }
/**
* @throws IllegalStateException if tunnel previously set, to protect saved checksum
*/
public void setReplyTunnel(TunnelId replyTunnel) {
if (_replyTunnel != null)
throw new IllegalStateException();
_replyTunnel = replyTunnel;
}
/**
* Does this router support encrypted replies?
*
* @param to null OK
* @since 0.9.7
*/
public static boolean supportsEncryptedReplies(RouterInfo to) {
if (to == null)
return false;
String v = to.getVersion();
return VersionComparator.comp(v, MIN_ENCRYPTION_VERSION) >= 0;
}
/**
* The included session key or null if unset
*
* @since 0.9.7
*/
public SessionKey getReplyKey() { return _replyKey; }
/**
* The included session tag or null if unset
*
* @since 0.9.7
*/
public SessionTag getReplyTag() { return _replyTag; }
/**
* Only worthwhile if sending reply via tunnel
*
* @throws IllegalStateException if key or tag previously set, to protect saved checksum
* @param encryptKey non-null
* @param encryptTag non-null
* @since 0.9.7
*/
public void setReplySession(SessionKey encryptKey, SessionTag encryptTag) {
if (_replyKey != null || _replyTag != null)
throw new IllegalStateException();
_replyKey = encryptKey;
_replyTag = encryptTag;
}
/**
* Set of peers that a lookup reply should NOT include.
* WARNING - returns a copy.
*
* @return Set of Hash objects, each of which is the H(routerIdentity) to skip, or null
*/
public Set<Hash> getDontIncludePeers() {
if (_dontIncludePeers == null)
return null;
return new HashSet<Hash>(_dontIncludePeers);
}
/**
* Replace the dontInclude set with this set.
* WARNING - makes a copy.
* Invalidates the checksum.
*
* @param peers may be null
*/
public void setDontIncludePeers(Collection<Hash> peers) {
_hasChecksum = false;
if (peers != null)
_dontIncludePeers = new ArrayList<Hash>(peers);
else
_dontIncludePeers = null;
}
/**
* Add to the set.
* Invalidates the checksum.
*
* @param peer non-null
* @since 0.8.12
*/
public void addDontIncludePeer(Hash peer) {
if (_dontIncludePeers == null)
_dontIncludePeers = new ArrayList<Hash>();
else if (_dontIncludePeers.contains(peer))
return;
_hasChecksum = false;
_dontIncludePeers.add(peer);
}
/**
* Add to the set.
* Invalidates the checksum.
*
* @param peers non-null
* @since 0.8.12
*/
public void addDontIncludePeers(Collection<Hash> peers) {
_hasChecksum = false;
if (_dontIncludePeers == null) {
_dontIncludePeers = new ArrayList<Hash>(peers);
} else {
for (Hash peer : peers) {
if (!_dontIncludePeers.contains(peer))
_dontIncludePeers.add(peer);
}
}
}
public void readMessage(byte data[], int offset, int dataSize, int type) throws I2NPMessageException {
if (type != MESSAGE_TYPE) throw new I2NPMessageException("Message type is incorrect for this message");
int curIndex = offset;
//byte keyData[] = new byte[Hash.HASH_LENGTH];
//System.arraycopy(data, curIndex, keyData, 0, Hash.HASH_LENGTH);
_key = Hash.create(data, curIndex);
curIndex += Hash.HASH_LENGTH;
//_key = new Hash(keyData);
//byte fromData[] = new byte[Hash.HASH_LENGTH];
//System.arraycopy(data, curIndex, fromData, 0, Hash.HASH_LENGTH);
_fromHash = Hash.create(data, curIndex);
curIndex += Hash.HASH_LENGTH;
//_fromHash = new Hash(fromData);
// as of 0.9.6, ignore other 7 bits of the flag byte
// TODO store the whole flag byte
boolean tunnelSpecified = (data[curIndex] & FLAG_TUNNEL) != 0;
boolean replyKeySpecified = (data[curIndex] & FLAG_ENCRYPT) != 0;
switch (data[curIndex] & FLAG_TYPE_MASK) {
case FLAG_TYPE_LS:
_type = Type.LS;
break;
case FLAG_TYPE_RI:
_type = Type.RI;
break;
case FLAG_TYPE_EXPL:
_type = Type.EXPL;
break;
case FLAG_TYPE_ANY:
default:
_type = Type.ANY;
break;
}
curIndex++;
if (tunnelSpecified) {
_replyTunnel = new TunnelId(DataHelper.fromLong(data, curIndex, 4));
curIndex += 4;
}
int numPeers = (int)DataHelper.fromLong(data, curIndex, 2);
curIndex += 2;
if ( (numPeers < 0) || (numPeers > MAX_NUM_PEERS) )
throw new I2NPMessageException("Invalid number of peers - " + numPeers);
List<Hash> peers = numPeers > 0 ? new ArrayList<Hash>(numPeers) : null;
for (int i = 0; i < numPeers; i++) {
//byte peer[] = new byte[Hash.HASH_LENGTH];
//System.arraycopy(data, curIndex, peer, 0, Hash.HASH_LENGTH);
Hash p = Hash.create(data, curIndex);
curIndex += Hash.HASH_LENGTH;
peers.add(p);
}
_dontIncludePeers = peers;
if (replyKeySpecified) {
byte[] rk = new byte[SessionKey.KEYSIZE_BYTES];
System.arraycopy(data, curIndex, rk, 0, SessionKey.KEYSIZE_BYTES);
_replyKey = new SessionKey(rk);
curIndex += SessionKey.KEYSIZE_BYTES;
// number of tags, assume always 1 for now
curIndex++;
byte[] rt = new byte[SessionTag.BYTE_LENGTH];
System.arraycopy(data, curIndex, rt, 0, SessionTag.BYTE_LENGTH);
_replyTag = new SessionTag(rt);
}
}
protected int calculateWrittenLength() {
int totalLength = 0;
totalLength += Hash.HASH_LENGTH*2; // key+fromHash
totalLength += 1; // hasTunnel?
if (_replyTunnel != null)
totalLength += 4;
totalLength += 2; // numPeers
if (_dontIncludePeers != null)
totalLength += Hash.HASH_LENGTH * _dontIncludePeers.size();
if (_replyKey != null)
// number of tags, assume always 1 for now
totalLength += SessionKey.KEYSIZE_BYTES + 1 + SessionTag.BYTE_LENGTH;
return totalLength;
}
protected int writeMessageBody(byte out[], int curIndex) throws I2NPMessageException {
if (_key == null) throw new I2NPMessageException("Key being searched for not specified");
if (_fromHash == null) throw new I2NPMessageException("From address not specified");
System.arraycopy(_key.getData(), 0, out, curIndex, Hash.HASH_LENGTH);
curIndex += Hash.HASH_LENGTH;
System.arraycopy(_fromHash.getData(), 0, out, curIndex, Hash.HASH_LENGTH);
curIndex += Hash.HASH_LENGTH;
// Generate the flag byte
byte flag;
if (_replyKey != null)
flag = FLAG_ENCRYPT;
else
flag = 0;
switch (_type) {
case LS:
flag |= FLAG_TYPE_LS;
break;
case RI:
flag |= FLAG_TYPE_RI;
break;
case EXPL:
flag |= FLAG_TYPE_EXPL;
break;
case ANY:
default:
// lookup type bits are 0
break;
}
if (_replyTunnel != null) {
flag |= FLAG_TUNNEL;
out[curIndex++] = flag;
DataHelper.toLong(out, curIndex, 4, _replyTunnel.getTunnelId());
curIndex += 4;
} else {
out[curIndex++] = flag;
}
if ( (_dontIncludePeers == null) || (_dontIncludePeers.isEmpty()) ) {
out[curIndex++] = 0x0;
out[curIndex++] = 0x0;
} else {
int size = _dontIncludePeers.size();
if (size > MAX_NUM_PEERS)
throw new I2NPMessageException("Too many peers: " + size);
DataHelper.toLong(out, curIndex, 2, size);
curIndex += 2;
for (Hash peer : _dontIncludePeers) {
System.arraycopy(peer.getData(), 0, out, curIndex, Hash.HASH_LENGTH);
curIndex += Hash.HASH_LENGTH;
}
}
if (_replyKey != null) {
System.arraycopy(_replyKey.getData(), 0, out, curIndex, SessionKey.KEYSIZE_BYTES);
curIndex += SessionKey.KEYSIZE_BYTES;
// number of tags, always 1 for now
out[curIndex++] = 1;
System.arraycopy(_replyTag.getData(), 0, out, curIndex, SessionTag.BYTE_LENGTH);
curIndex += SessionTag.BYTE_LENGTH;
}
return curIndex;
}
public int getType() { return MESSAGE_TYPE; }
@Override
public int hashCode() {
return DataHelper.hashCode(_key) +
DataHelper.hashCode(_fromHash) +
DataHelper.hashCode(_replyTunnel) +
DataHelper.hashCode(_dontIncludePeers);
}
@Override
public boolean equals(Object object) {
if ( (object != null) && (object instanceof DatabaseLookupMessage) ) {
DatabaseLookupMessage msg = (DatabaseLookupMessage)object;
return DataHelper.eq(_key, msg._key) &&
DataHelper.eq(_fromHash, msg._fromHash) &&
DataHelper.eq(_replyTunnel, msg._replyTunnel) &&
DataHelper.eq(_dontIncludePeers, msg._dontIncludePeers);
} else {
return false;
}
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder(256);
buf.append("[DatabaseLookupMessage: ");
buf.append("\n\tSearch Type: ").append(_type);
buf.append("\n\tSearch Key: ").append(_key);
if (_replyKey != null)
buf.append("\n\tReply GW: ");
else
buf.append("\n\tFrom: ");
buf.append(_fromHash);
buf.append("\n\tReply Tunnel: ").append(_replyTunnel);
if (_replyKey != null)
buf.append("\n\tReply Key: ").append(_replyKey);
if (_replyTag != null)
buf.append("\n\tReply Tag: ").append(_replyTag);
if (_dontIncludePeers != null) {
buf.append("\n\tDon't Include Peers: ");
buf.append(_dontIncludePeers.size());
}
buf.append("]");
return buf.toString();
}
}