net.i2p.router.tunnel.pool

Class TunnelPeerSelector

java.lang.Object

net.i2p.router.tunnel.pool.ConnectChecker

net.i2p.router.tunnel.pool.TunnelPeerSelector

Direct Known Subclasses:

ClientPeerSelector, ExploratoryPeerSelector

public abstract class TunnelPeerSelector
extends ConnectChecker

Coordinate the selection of peers to go into a tunnel for one particular pool.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	TunnelPeerSelector.Excluder Excluder that automatically adds peers to the set when they should be excluded.
protected class	TunnelPeerSelector.HopChainValidator Validates peer-to-peer connectivity in a tunnel hop chain.

Field Summary

Fields inherited from class net.i2p.router.tunnel.pool.ConnectChecker

ANY_V4, ctx, log

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TunnelPeerSelector(RouterContext context)

Method Summary

Modifier and Type	Method and Description
protected boolean	allowAsIBGW(Hash h) Should we allow as IBGW? This just checks for the "R" capability and IPv4 support.
protected boolean	allowAsOBEP(Hash h) Should we allow as OBEP? This just checks for IPv4 support.
protected boolean	checkTunnel(boolean isInbound, boolean isExploratory, List<Hash> tunnel) Connectivity check.
protected boolean	filterSlow(boolean isInbound, boolean isExploratory) do we want to skip peers that are slow?
protected Set<Hash>	getClosestHopExclude(boolean isInbound, Set<Hash> toAdd) Pick peers that we want to avoid for the first OB hop or last IB hop.
protected Set<Hash>	getExclude(boolean isInbound, boolean isExploratory) As of 0.9.58, this returns a set populated only by TunnelManager.selectPeersInTooManyTunnels(), for passing to ProfileOrganizer.
protected int	getLength(TunnelPoolSettings settings)
protected int	getPeerConnectMask(RouterInfo ri) Get the connect mask for a peer's addresses.
protected boolean	isDuplicateSequence(TunnelPoolSettings settings, List<Hash> newPeers) Check if the selected peer sequence matches an existing tunnel in the pool.
protected boolean	isIPv6Only() Are we IPv6 only?
protected void	orderPeers(List<Hash> rv, SessionKey key) see HashComparator
protected List<Hash>	regeneratePeers(TunnelPoolSettings settings, List<Hash> peers) Regenerate tunnel peers to avoid duplicate sequence.
protected List<Hash>	selectExplicit(TunnelPoolSettings settings, int length) For debugging, also possibly for restricted routes.
abstract List<Hash>	selectPeers(TunnelPoolSettings settings) Which peers should go into the next tunnel for the given settings?
static boolean	shouldExclude(RouterContext ctx, RouterInfo peer) Should the peer be excluded based on its published caps, crypto, and version?
protected boolean	shouldSelectExplicit(TunnelPoolSettings settings) For debugging, also possibly for restricted routes? Needs analysis and testing

Methods inherited from class net.i2p.router.tunnel.pool.ConnectChecker

canConnect, canConnect, canConnect, getConnectMask, getInboundMask, getOutboundMask, isNTCPDisabled, isSSUDisabled

Methods inherited from class java.lang.Object

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

Constructor Detail

TunnelPeerSelector

protected TunnelPeerSelector(RouterContext context)

Method Detail

allowAsIBGW

protected boolean allowAsIBGW(Hash h)

Should we allow as IBGW? This just checks for the "R" capability and IPv4 support. Will return false for hidden or IPv6-only. This is intended for tunnel candidates, where we already have the RI. Will not force RI lookups. Default true.

allowAsOBEP

protected boolean allowAsOBEP(Hash h)

Should we allow as OBEP? This just checks for IPv4 support. Will return false for IPv6-only. This is intended for tunnel candidates, where we already have the RI. Will not force RI lookups. Default true.

checkTunnel

protected boolean checkTunnel(boolean isInbound,
                              boolean isExploratory,
                              List<Hash> tunnel)

Connectivity check. Check that each hop can connect to the next, including us. Check that the OBEP is not IPv6-only, and the IBGW is reachable and not hidden or IPv6-only. Tells the profile manager to blame the hop, and returns false on failure.

Parameters:

tunnel - ENDPOINT FIRST, GATEWAY LAST!!!!, length 2 or greater

Returns:

ok

filterSlow

protected boolean filterSlow(boolean isInbound,
                             boolean isExploratory)

do we want to skip peers that are slow?

Returns:

true unless configured otherwise

getClosestHopExclude

protected Set<Hash> getClosestHopExclude(boolean isInbound,
                                         Set<Hash> toAdd)

Pick peers that we want to avoid for the first OB hop or last IB hop. There's several cases of importance:

1. Inbound and we are hidden - Exclude all unless connected. This is taken care of in ClientPeerSelector and TunnelPeerSelector selectPeers(), not here.
2. We are IPv6-only. Exclude all v4-only peers, unless connected This is taken care of here.
3. We have NTCP or SSU disabled. Exclude all incompatible peers, unless connected This is taken care of here.
4. Minimum version check, if we are some brand-new sig type, or are using some new tunnel build method. Not currently used, but this is where to implement the checks if needed. Make sure that ClientPeerSelector and TunnelPeerSelector selectPeers() call this when needed.

As of 0.9.58, this a set with only toAdd, for use in ProfileOrganizer. The set will be populated via the contains() calls.

Parameters:

isInbound -

Returns:

non-null

getExclude

protected Set<Hash> getExclude(boolean isInbound,
                               boolean isExploratory)

As of 0.9.58, this returns a set populated only by TunnelManager.selectPeersInTooManyTunnels(), for passing to ProfileOrganizer. The set will be populated via the contains() calls.

getLength

protected int getLength(TunnelPoolSettings settings)

Returns:

randomized number of hops 0-7, not including ourselves

getPeerConnectMask

protected int getPeerConnectMask(RouterInfo ri)

Get the connect mask for a peer's addresses. Wrapper around parent's private static method.

isDuplicateSequence

protected boolean isDuplicateSequence(TunnelPoolSettings settings,
                                      List<Hash> newPeers)

Check if the selected peer sequence matches an existing tunnel in the pool. Prevents duplicate peer sequences which could weaken anonymity.

Parameters:

settings - the tunnel pool settings

newPeers - the newly selected peers (excluding self)

Returns:

true if duplicate detected

isIPv6Only

protected boolean isIPv6Only()

Are we IPv6 only?

orderPeers

protected void orderPeers(List<Hash> rv,
                          SessionKey key)

see HashComparator

regeneratePeers

protected List<Hash> regeneratePeers(TunnelPoolSettings settings,
                                     List<Hash> peers)

Regenerate tunnel peers to avoid duplicate sequence. Shuffles the peer selection and re-orders.

Parameters:

settings - the tunnel pool settings

peers - the peers to regenerate

Returns:

regenerated peer list (same or different)

selectExplicit

protected List<Hash> selectExplicit(TunnelPoolSettings settings,
                                    int length)

For debugging, also possibly for restricted routes. Needs analysis and testing

Parameters:

settings - the tunnel pool settings

length - the desired length of the tunnel

Returns:

the list of explicit peer hashes for the tunnel

selectPeers

public abstract List<Hash> selectPeers(TunnelPoolSettings settings)

Which peers should go into the next tunnel for the given settings?

Returns:

ordered list of Hash objects (one per peer) specifying what order they should appear in a tunnel (ENDPOINT FIRST). This includes the local router in the list. If there are no tunnels or peers to build through, and the settings reject 0 hop tunnels, this will return null.

shouldExclude

public static boolean shouldExclude(RouterContext ctx,
                                    RouterInfo peer)

Should the peer be excluded based on its published caps, crypto, and version?

Parameters:

ctx - Router context for peer count checks

peer - The peer to evaluate

Returns:

true if the peer should be excluded

shouldSelectExplicit

protected boolean shouldSelectExplicit(TunnelPoolSettings settings)

For debugging, also possibly for restricted routes? Needs analysis and testing

Returns:

usually false