net.i2p.i2ptunnel

Class ConnThrottler

java.lang.Object

net.i2p.i2ptunnel.ConnThrottler

class ConnThrottler
extends Object

Connection rate limiter providing basic DoS protection.

Counts events per peer and across all peers. Ban time differs from check time, with separate map of throttled peers and individual timestamps.

Differs from streaming version: more precise tracking vs. lightweight but "sloppy" single time bucket approach.

Constructor Summary

Constructors

Constructor and Description
ConnThrottler(int max, int totalMax, long period, long throttlePeriod, long totalThrottlePeriod, String action, Log log)

Method Summary

Modifier and Type	Method and Description
void	clear() Resets all throttling state.
boolean	shouldThrottle(Hash h) Checks if a peer or the total connection rate exceeds configured limits.
void	start() Starts the throttler by scheduling the cleanup timer.
void	stop() Stops the throttler and resets all state.
void	updateLimits(int max, int totalMax, long checkPeriod, long throttlePeriod, long totalThrottlePeriod) Updates the rate limiting configuration.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConnThrottler

public ConnThrottler(int max,
                     int totalMax,
                     long period,
                     long throttlePeriod,
                     long totalThrottlePeriod,
                     String action,
                     Log log)

Method Detail

clear

public void clear()

Resets all throttling state.

This method clears all peer records, resets the total connection counter, and clears the total throttle timer. After calling this method, all connections will be allowed until limits are exceeded again.

shouldThrottle

public boolean shouldThrottle(Hash h)

Checks if a peer or the total connection rate exceeds configured limits.

This method increments the connection counter for the given peer and checks if either the per-peer limit or the total connection limit has been exceeded. If a limit is exceeded, the peer (or all peers) is throttled for the configured throttle period.

Throttle Logic:

• Individual: If max connections exceeded in checkPeriod, throttle for throttlePeriod
• Total: If total connections exceeded, throttle all for totalThrottlePeriod

Parameters:

h - the peer's destination hash to check

Returns:

true if the peer should be throttled (request denied), false otherwise

start

public void start()

Starts the throttler by scheduling the cleanup timer.

This method must be called to begin rate limiting. The cleanup timer will run periodically to check for expired throttles and clean up stale peer records.

If already started, this method has no effect.

stop

public void stop()

Stops the throttler and resets all state.

This method cancels the cleanup timer, clears all peer records, and resets the total connection counter. The throttler may be restarted by calling start() again.

updateLimits

public void updateLimits(int max,
                         int totalMax,
                         long checkPeriod,
                         long throttlePeriod,
                         long totalThrottlePeriod)

Updates the rate limiting configuration.

All period values are enforced with a minimum of 10 seconds.

Parameters:

max - the maximum number of connections per peer (0 for unlimited)

totalMax - the maximum total connections from all peers (0 for unlimited)

checkPeriod - the time window for counting connections, in milliseconds

throttlePeriod - how long to throttle individual peers, in milliseconds

totalThrottlePeriod - how long to throttle all peers, in milliseconds