Simple Module Kademlia

Package: oversim.overlay.kademlia
File: src/overlay/kademlia/Kademlia.ned

The main module of the Kademlia implementation

Author: Sebastian Mies, Ingmar Baumgart, Bernhard Heep

Usage diagram:

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Inheritance diagram:

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Extends:

Name	Type	Description
BaseOverlay	simple module	Base class for overlay implementations

Used in compound modules:

Name	Type	Description
KademliaModules	compound module	Implementation of the Kademlia DHT overlay as described in "Kademlia: A peer-to-peer information system based on the XOR metric" by P. Maymounkov and D. Mazieres, published in "In Proceedings of IPTPS02"

Parameters:

Name	Type	Description
rpcUdpTimeout	double	default timeout value for direct RPCs
rpcKeyTimeout	double	default timeout value for routed RPCs
optimizeTimeouts	bool	calculate timeouts from measured RTTs and network coordinates
rpcExponentialBackoff	bool	if true, doubles the timeout for every retransmission
localPort	int	UDP port for overlay messages
overlayId	int	identifies the overlay this node belongs to (used for multiple overlays)
debugOutput	bool	enable debug output
keyLength	int	overlay key length in bits
nodeId	string	optional nodeId as string in hexadecimal notation
useCommonAPIforward	bool	enable CommonAPI forward() calls
drawOverlayTopology	bool	draw arrow to successor node?
hopCountMax	int	maximum number of overlay hops
recNumRedundantNodes	int	numRedundantNodes for recursive routing
joinOnApplicationRequest	bool	only join the overlay on application request
collectPerHopDelay	bool	delay statistics for single hops
routeMsgAcks	bool	use RPCs for route messages
lookupRedundantNodes	int	number of next hops in each step
lookupParallelPaths	int	number of parallel paths
lookupParallelRpcs	int	number of nodes to ask in parallel
lookupVerifySiblings	bool	true, if siblings need to be authenticated with a ping
lookupMajoritySiblings	bool	true, if sibling candidates are selected by a majority decision if using parallel paths
lookupMerge	bool	true, if parallel Rpc results should be merged
lookupFailedNodeRpcs	bool	communicate failed nodes
lookupStrictParallelRpcs	bool	limited the number of concurrent rpcs to parameter parallelRpcs
lookupUseAllParallelResponses	bool	merge all parallel responses from earlier steps
lookupNewRpcOnEveryTimeout	bool	send a new RPC immediately after an RPC timeouts
lookupNewRpcOnEveryResponse	bool	send a new RPC after every response, even if there was no progress
lookupFinishOnFirstUnchanged	bool	finish lookup, if the last pending RPC returned without progress
lookupVisitOnlyOnce	bool	if true, the same node is never asked twice during a single lookup
lookupAcceptLateSiblings	bool	if true, a FindNodeResponse with sibling flag set is always accepted, even if it is from a previous lookup step
routingType	string	default routing mode (iterative, semi-recursive,...)
rejoinOnFailure	bool	rejoin after loosing connection to the overlay?
sendRpcResponseToLastHop	bool	needed by KBR protocols for NAT support
recordRoute	bool	record visited hops on route
dropFindNodeAttack	bool	if node is malicious, it tries a findNode attack
isSiblingAttack	bool	if node is malicious, it tries a isSibling attack
invalidNodesAttack	bool	if node is malicious, it tries a invalidNode attack
dropRouteMessageAttack	bool	if node is malicious, it drops all received BaseRouteMessages
measureAuthBlock	bool	if true, measure the overhead of signatures in rpc messages
restoreContext	bool	if true, a node rejoins with its old nodeId and malicious state
minSiblingTableRefreshInterval	double	siblingTable refresh delay
minBucketRefreshInterval	double	bucket refresh delay
siblingPingInterval	double	interval in which all siblings get pinged (0 to disable)
maxStaleCount	int	number of timeouts before node removal
k	int	number of paths (size of k-bucket)
b	int	network diameter O(log_{2^(b)})
s	int	number of siblings
exhaustiveRefresh	bool	if true, use exhaustive-iterative lookups to refresh buckets
pingNewSiblings	bool	ping new unknown siblings?
secureMaintenance	bool	if true, ping not authenticated nodes before adding them to a bucket
newMaintenance	bool
enableReplacementCache	bool	enables the replacement cache to store nodes if a bucket is full
replacementCachePing	bool	ping the least recently used node in a full bucket, when a node is added to the replacement cache
replacementCandidates	int	maximum number of candidates in the replacement cache for each bucket
siblingRefreshNodes	int	number of redundant nodes for exhaustive sibling table refresh lookups (0 = numRedundantNodes)
bucketRefreshNodes	int	number of redundant nodes for exhaustive bucket refresh lookups (0 = numRedundantNodes)
activePing	bool	R/Kademlia
proximityRouting	bool	enable proximity routing (recursive only)
proximityNeighborSelection	bool	enable proximity neighbor selection
altRecMode	bool	use source-routing mode instead of direct mode

Properties:

Name	Value	Description
class	Kademlia
display	i=block/circle

Gates:

Name	Direction	Description
udpIn	input	gate from the UDP layer
udpOut	output	gate to the UDP layer
tcpIn	input	gate from the TCP layer
tcpOut	output	gate to the TCP layer
appIn	input	gate from the application
appOut	output	gate to the application
direct_in	input	gate for sendDirect

Source code:

//
// The main module of the Kademlia implementation
//
// @author Sebastian Mies, Ingmar Baumgart, Bernhard Heep
//
simple Kademlia extends BaseOverlay
{
    parameters:
        @class(Kademlia);
        double minSiblingTableRefreshInterval @unit(s); // siblingTable refresh delay
        double minBucketRefreshInterval @unit(s); // bucket refresh delay
        double siblingPingInterval @unit(s); // interval in which all siblings get pinged (0 to disable)
        int maxStaleCount; // number of timeouts before node removal
        int k; // number of paths (size of k-bucket)
        int b; // network diameter O(log_{2^(b)})
        int s; // number of siblings
        bool exhaustiveRefresh; // if true, use exhaustive-iterative lookups to refresh buckets
        bool pingNewSiblings; // ping new unknown siblings?
        bool secureMaintenance; // if true, ping not authenticated nodes before adding them to a bucket
        bool newMaintenance;

        bool enableReplacementCache; // enables the replacement cache to store nodes if a bucket is full
        bool replacementCachePing; // ping the least recently used node in a full bucket, when a node is added to the replacement cache
        int replacementCandidates; // maximum number of candidates in the replacement cache for each bucket
        int siblingRefreshNodes; // number of redundant nodes for exhaustive sibling table refresh lookups (0 = numRedundantNodes)
        int bucketRefreshNodes; // number of redundant nodes for exhaustive bucket refresh lookups (0 = numRedundantNodes)

        // R/Kademlia
        bool activePing; // ping new neighbors?
        bool proximityRouting; // enable proximity routing (recursive only)
        bool proximityNeighborSelection; // enable proximity neighbor selection
        bool altRecMode; // use source-routing mode instead of direct mode
}