net.i2p.router.networkdb.kademlia

Class LookupBanHammer

java.lang.Object

net.i2p.router.networkdb.kademlia.LookupBanHammer

class LookupBanHammer
extends Object

Tracks the frequency of recent lookup requests targeting a specific reply peer/tunnel pair to provide basic denial-of-service (DOS) protection by banning excessive requesters.

Uses burst detection over a sliding 1-second window and an overall lookup count threshold to decide when to ban peers. Bans last for a fixed duration and expire automatically.

Thread-safe implementation utilizing concurrent data structures and finer-grained synchronization for improved performance under concurrent access.

This mechanism is a partial DOS protection and does not prevent spoofed reply identifiers or multiple reply tunnels.

Constructor Summary

Constructors

Constructor and Description
LookupBanHammer() Constructs a newly initialized LookupBanHammer instance.

Method Summary

Modifier and Type	Method and Description
(package private) boolean	shouldBan(Hash key, TunnelId id) Records a lookup request from a requester identified by key and tunnel ID, and determines whether the requester should be banned based on recent activity.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LookupBanHammer

LookupBanHammer()

Constructs a newly initialized LookupBanHammer instance. Registers a periodic cleanup event to remove expired bans and reset counters.

Method Detail

shouldBan

boolean shouldBan(Hash key,
                  TunnelId id)

Records a lookup request from a requester identified by key and tunnel ID, and determines whether the requester should be banned based on recent activity.

This method increments the request count for the requester, tracks burst-frequency within a sliding window, and enforces bans if thresholds are exceeded.

Parameters:

key - non-null Hash representing the requester identifying key

id - TunnelId of the target reply tunnel, or null if direct lookups

Returns:

true if the requester is currently banned and should be blocked; false otherwise