zzz/i2p.i2p
1
0
Fork 0
forked from I2P_Developers/i2p.i2p
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Router: Fix Bloom filter false positives

Browse Source 
caused by lack of sync around buffers.
Use temp buffers instead.
Most likely to affect high-bandwidth or testnet routers;
appears to be rare on lower-bandwidth routers.
This commit is contained in:
zzz
2019-08-02 15:48:05 +00:00
parent 8158753dac
commit 8ed0dd2a5c
3 changed files with 35 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
router/java/src/net/i2p/router/RouterVersion.java
View File

@@ -18,7 +18,7 @@ public class RouterVersion {
/** deprecated */
public final static String ID = "Monotone";
public final static String VERSION = CoreVersion.VERSION;
public final static long BUILD = 4;
public final static long BUILD = 5;
/** for example "-test" */
public final static String EXTRA = "";

47
router/java/src/net/i2p/router/util/DecayingBloomFilter.java
View File

@@ -32,8 +32,6 @@ public class DecayingBloomFilter {
protected final int _durationMs;
protected final int _entryBytes;
private final byte _extenders[][];
private final byte _extended[];
private final byte _longToEntry[];
private final long _longToEntryMask;
protected long _currentDuplicates;
protected volatile boolean _keepDecaying;
@@ -57,8 +55,6 @@ public class DecayingBloomFilter {
_durationMs = durationMs;
// all final
_extenders = null;
_extended = null;
_longToEntry = null;
_longToEntryMask = 0;
context.addShutdownTask(new Shutdown());
_keepDecaying = true;
@@ -121,17 +117,15 @@ public class DecayingBloomFilter {
int numExtenders = (32+ (entryBytes-1))/entryBytes - 1;
if (numExtenders < 0)
numExtenders = 0;
_extenders = new byte[numExtenders][entryBytes];
for (int i = 0; i < numExtenders; i++)
_context.random().nextBytes(_extenders[i]);
if (numExtenders > 0) {
_extended = new byte[32];
_longToEntry = new byte[_entryBytes];
_extenders = new byte[numExtenders][entryBytes];
for (int i = 0; i < numExtenders; i++) {
_context.random().nextBytes(_extenders[i]);
}
_longToEntryMask = (1l << (_entryBytes * 8l)) -1;
} else {
// final
_extended = null;
_longToEntry = null;
_extenders = null;
_longToEntryMask = 0;
}
_keepDecaying = true;
@@ -208,18 +202,19 @@ public class DecayingBloomFilter {
*/
public boolean add(long entry) {
if (ALWAYS_MISS) return false;
byte[] longToEntry = new byte[_entryBytes];
if (_entryBytes <= 7)
entry = ((entry ^ _longToEntryMask) & ((1 << 31)-1)) | (entry ^ _longToEntryMask);
//entry &= _longToEntryMask;
if (entry < 0) {
DataHelper.toLong(_longToEntry, 0, _entryBytes, 0-entry);
_longToEntry[0] |= (1 << 7);
DataHelper.toLong(longToEntry, 0, _entryBytes, 0-entry);
longToEntry[0] |= (1 << 7);
} else {
DataHelper.toLong(_longToEntry, 0, _entryBytes, entry);
DataHelper.toLong(longToEntry, 0, _entryBytes, entry);
}
getReadLock();
try {
return locked_add(_longToEntry, 0, _longToEntry.length, true);
return locked_add(longToEntry, 0, _entryBytes, true);
} finally { releaseReadLock(); }
}
@@ -230,28 +225,30 @@ public class DecayingBloomFilter {
*/
public boolean isKnown(long entry) {
if (ALWAYS_MISS) return false;
byte[] longToEntry = new byte[_entryBytes];
if (_entryBytes <= 7)
entry = ((entry ^ _longToEntryMask) & ((1 << 31)-1)) | (entry ^ _longToEntryMask);
if (entry < 0) {
DataHelper.toLong(_longToEntry, 0, _entryBytes, 0-entry);
_longToEntry[0] |= (1 << 7);
DataHelper.toLong(longToEntry, 0, _entryBytes, 0-entry);
longToEntry[0] |= (1 << 7);
} else {
DataHelper.toLong(_longToEntry, 0, _entryBytes, entry);
DataHelper.toLong(longToEntry, 0, _entryBytes, entry);
}
getReadLock();
try {
return locked_add(_longToEntry, 0, _longToEntry.length, false);
return locked_add(longToEntry, 0, _entryBytes, false);
} finally { releaseReadLock(); }
}
private boolean locked_add(byte entry[], int offset, int len, boolean addIfNew) {
if (_extended != null) {
if (_extenders != null) {
// extend the entry to 32 bytes
System.arraycopy(entry, offset, _extended, 0, len);
for (int i = 0; i < _extenders.length; i++)
DataHelper.xor(entry, offset, _extenders[i], 0, _extended, _entryBytes * (i+1), _entryBytes);
BloomSHA1.FilterKey key = _current.getFilterKey(_extended, 0, 32);
byte[] extended = new byte[32];
System.arraycopy(entry, offset, extended, 0, len);
for (int i = 0; i < _extenders.length; i++) {
DataHelper.xor(entry, offset, _extenders[i], 0, extended, _entryBytes * (i+1), _entryBytes);
}
BloomSHA1.FilterKey key = _current.getFilterKey(extended, 0, 32);
boolean seen = _current.locked_member(key);
if (!seen)
seen = _previous.locked_member(key);