Files
i2p.itoopie/router/java/src/net/i2p/data/i2np/DatabaseLookupMessage.java
2006-04-05 17:08:04 +00:00

250 lines
9.3 KiB
Java

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.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import net.i2p.I2PAppContext;
import net.i2p.data.DataHelper;
import net.i2p.data.Hash;
import net.i2p.data.TunnelId;
import net.i2p.util.Log;
/**
* Defines the message a router sends to another router to search for a
* key in the network database.
*
* @author jrandom
*/
public class DatabaseLookupMessage extends I2NPMessageImpl {
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;
private Set _dontIncludePeers;
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;
public DatabaseLookupMessage(I2PAppContext context) {
this(context, false);
}
public DatabaseLookupMessage(I2PAppContext context, boolean locallyCreated) {
super(context);
//setSearchKey(null);
//setFrom(null);
//setDontIncludePeers(null);
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"));
}
}
}
/**
* 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; }
public void setSearchKey(Hash key) { _key = key; }
/**
* Contains the router who requested this lookup
*
*/
public Hash getFrom() { return _fromHash; }
public void setFrom(Hash from) { _fromHash = from; }
/**
* Contains the tunnel ID a reply should be sent to
*
*/
public TunnelId getReplyTunnel() { return _replyTunnel; }
public void setReplyTunnel(TunnelId replyTunnel) { _replyTunnel = replyTunnel; }
/**
* Set of peers that a lookup reply should NOT include
*
* @return Set of Hash objects, each of which is the H(routerIdentity) to skip
*/
public Set getDontIncludePeers() { return _dontIncludePeers; }
public void setDontIncludePeers(Set peers) {
if (peers != null)
_dontIncludePeers = new HashSet(peers);
else
_dontIncludePeers = null;
}
public void readMessage(byte data[], int offset, int dataSize, int type) throws I2NPMessageException, IOException {
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);
curIndex += Hash.HASH_LENGTH;
_key = new Hash(keyData);
byte fromData[] = new byte[Hash.HASH_LENGTH];
System.arraycopy(data, curIndex, fromData, 0, Hash.HASH_LENGTH);
curIndex += Hash.HASH_LENGTH;
_fromHash = new Hash(fromData);
boolean tunnelSpecified = false;
switch (data[curIndex]) {
case DataHelper.BOOLEAN_TRUE:
tunnelSpecified = true;
break;
case DataHelper.BOOLEAN_FALSE:
tunnelSpecified = false;
break;
default:
throw new I2NPMessageException("Tunnel must be explicitly specified (or not)");
}
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 >= (1<<16) ) )
throw new I2NPMessageException("Invalid number of peers - " + numPeers);
Set peers = new HashSet(numPeers);
for (int i = 0; i < numPeers; i++) {
byte peer[] = new byte[Hash.HASH_LENGTH];
System.arraycopy(data, curIndex, peer, 0, Hash.HASH_LENGTH);
curIndex += Hash.HASH_LENGTH;
peers.add(new Hash(peer));
}
_dontIncludePeers = peers;
}
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();
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;
if (_replyTunnel != null) {
out[curIndex++] = DataHelper.BOOLEAN_TRUE;
byte id[] = DataHelper.toLong(4, _replyTunnel.getTunnelId());
System.arraycopy(id, 0, out, curIndex, 4);
curIndex += 4;
} else {
out[curIndex++] = DataHelper.BOOLEAN_FALSE;
}
if ( (_dontIncludePeers == null) || (_dontIncludePeers.size() <= 0) ) {
out[curIndex++] = 0x0;
out[curIndex++] = 0x0;
} else {
byte len[] = DataHelper.toLong(2, _dontIncludePeers.size());
out[curIndex++] = len[0];
out[curIndex++] = len[1];
for (Iterator iter = _dontIncludePeers.iterator(); iter.hasNext(); ) {
Hash peer = (Hash)iter.next();
System.arraycopy(peer.getData(), 0, out, curIndex, Hash.HASH_LENGTH);
curIndex += Hash.HASH_LENGTH;
}
}
return curIndex;
}
public int getType() { return MESSAGE_TYPE; }
public int hashCode() {
return DataHelper.hashCode(getSearchKey()) +
DataHelper.hashCode(getFrom()) +
DataHelper.hashCode(getReplyTunnel()) +
DataHelper.hashCode(_dontIncludePeers);
}
public boolean equals(Object object) {
if ( (object != null) && (object instanceof DatabaseLookupMessage) ) {
DatabaseLookupMessage msg = (DatabaseLookupMessage)object;
return DataHelper.eq(getSearchKey(),msg.getSearchKey()) &&
DataHelper.eq(getFrom(),msg.getFrom()) &&
DataHelper.eq(getReplyTunnel(),msg.getReplyTunnel()) &&
DataHelper.eq(_dontIncludePeers,msg.getDontIncludePeers());
} else {
return false;
}
}
public String toString() {
StringBuffer buf = new StringBuffer();
buf.append("[DatabaseLookupMessage: ");
buf.append("\n\tSearch Key: ").append(getSearchKey());
buf.append("\n\tFrom: ").append(getFrom());
buf.append("\n\tReply Tunnel: ").append(getReplyTunnel());
buf.append("\n\tDont Include Peers: ");
if (_dontIncludePeers != null)
buf.append(_dontIncludePeers.size());
buf.append("]");
return buf.toString();
}
}