Package org.klomp.snark.dht

Class KRPC

  • All Implemented Interfaces:
    I2PSessionListener, I2PSessionMuxedListener, DHT
    public class KRPC
extends Object
implements I2PSessionMuxedListener, DHT
    Standard BEP 5 Mods for I2P: 
     - The UDP port need not be pinged after receiving a PORT message.

 - The UDP (datagram) port listed in the compact node info is used
   to receive repliable (signed) datagrams.
   This is used for queries, except for announces.
   We call this the "query port".
   In addition to that UDP port, we use a second datagram
   port equal to the signed port + 1. This is used to receive
   unsigned (raw) datagrams for replies, errors, and announce queries..
   We call this the "response port".

 - Compact peer info is 32 bytes (32 byte SHA256 Hash)
   instead of 4 byte IP + 2 byte port. There is no peer port.

 - Compact node info is 54 bytes (20 byte SHA1 Hash + 32 byte SHA256 Hash + 2 byte port)
   instead of 20 byte SHA1 Hash + 4 byte IP + 2 byte port.
   Port is the query port, the response port is always the query port + 1.

 - The trackerless torrent dictionary "nodes" key is a list of
   32 byte binary strings (SHA256 Hashes) instead of a list of lists
   containing a host string and a port integer.
    Questions: - nodes (in the find_node and get_peers response) is one concatenated string, not a list of strings, right? - Node ID enforcement, keyspace rotation?
    Since:
    0.9.2
    Author:
    zzz

    • Method Detail

      • size

        public int size()
        Known nodes, not estimated total network size.
        Specified by:
        size in interface DHT

      • getPort

        public int getPort()
        Specified by:
        getPort in interface DHT
        Returns:
        The UDP query port

      • getRPort

        public int getRPort()
        Specified by:
        getRPort in interface DHT
        Returns:
        The UDP response port

      • ping

        public void ping​(Destination dest,
                 int port)
        Ping. We don't have a NID yet so the node is presumed to be absent from our DHT. Non-blocking, does not wait for pong. If and when the pong is received the node will be inserted in our DHT.
        Specified by:
        ping in interface DHT

      • findClosest

        public List<NodeInfo> findClosest​(byte[] ih,
                                  int max)
        Local lookup only
        Parameters:
        ih - a 20-byte info hash
        max - max to return
        Returns:
        list or empty list (never null)

      • getPeersAndAnnounce

        public Collection<Hash> getPeersAndAnnounce​(byte[] ih,
                                            int max,
                                            long maxWait,
                                            int annMax,
                                            long annMaxWait,
                                            boolean isSeed,
                                            boolean noSeeds)
        Get peers for a torrent, and announce to the closest annMax nodes we find. This is an iterative lookup in the DHT. Blocking! Caller should run in a thread.
        Specified by:
        getPeersAndAnnounce in interface DHT
        Parameters:
        ih - the Info Hash (torrent)
        max - maximum number of peers to return
        maxWait - the maximum time to wait (ms) must be > 0
        annMax - the number of peers to announce to
        annMaxWait - the maximum total time to wait for announces, may be 0 to return immediately without waiting for acks
        isSeed - true if seed, false if leech
        noSeeds - true if we do not want seeds in the result
        Returns:
        possibly empty (never null)

      • announce

        public void announce​(byte[] ih,
                     boolean isSeed)
        Announce to ourselves. Non-blocking.
        Specified by:
        announce in interface DHT
        Parameters:
        ih - the Info Hash (torrent)

      • announce

        public void announce​(byte[] ih,
                     byte[] peerHash,
                     boolean isSeed)
        Announce somebody else we know about to ourselves. Non-blocking.
        Specified by:
        announce in interface DHT
        Parameters:
        ih - the Info Hash (torrent)
        peerHash - the peer's Hash

      • unannounce

        public void unannounce​(byte[] ih)
        Remove reference to ourselves in the local tracker. Use when shutting down the torrent locally. Non-blocking.
        Specified by:
        unannounce in interface DHT
        Parameters:
        ih - the Info Hash (torrent)

      • announce

        public int announce​(byte[] ih,
                    int max,
                    long maxWait,
                    boolean isSeed)
        Not recommended - use getPeersAndAnnounce(). Announce to the closest peers in the local DHT. This is NOT iterative - call getPeers() first to get the closest peers into the local DHT. Blocking unless maxWait <= 0 Caller should run in a thread. This also automatically announces ourself to our local tracker. For best results do a getPeersAndAnnounce() instead, as this announces to the closest in the kbuckets, it does NOT sort through the known nodes hashmap.
        Specified by:
        announce in interface DHT
        Parameters:
        ih - the Info Hash (torrent)
        max - maximum number of peers to announce to
        maxWait - the maximum total time to wait (ms) or 0 to do all in parallel and return immediately.
        isSeed - true if seed, false if leech
        Returns:
        the number of successful announces, not counting ourselves.

      • start

        public void start()
        Loads the DHT from file. Can't be restarted after stopping?

      • stop

        public void stop()
        Stop everything.
        Specified by:
        stop in interface DHT

      • clear

        public void clear()
        Clears the tracker and DHT data. Call after saving DHT data to disk.

      • renderStatusHTML

        public String renderStatusHTML()
        Debug info, HTML formatted
        Specified by:
        renderStatusHTML in interface DHT

      • heardAbout

        NodeInfo heardAbout​(NodeInfo nInfo)
        Called for bootstrap or for all nodes in a receiveNodes reply. Package private for PersistDHT.
        Returns:
        non-null nodeInfo from DB if present, otherwise the nInfo parameter is returned

      • messageAvailable

        public void messageAvailable​(I2PSession session,
                             int msgId,
                             long size,
                             int proto,
                             int fromPort,
                             int toPort)
        Instruct the client that the given session has received a message Will be called only if you register via addMuxedSessionListener(). Will be called only for the proto(s) and toPort(s) you register for.
        Specified by:
        messageAvailable in interface I2PSessionMuxedListener
        Parameters:
        session - session to notify
        msgId - message number available
        size - size of the message - why it's a long and not an int is a mystery
        proto - 1-254 or 0 for unspecified
        fromPort - 1-65535 or 0 for unspecified
        toPort - 1-65535 or 0 for unspecified

      • reportAbuse

        public void reportAbuse​(I2PSession session,
                        int severity)
        Description copied from interface: I2PSessionMuxedListener
        Instruct the client that the session specified seems to be under attack and that the client may wish to move its destination to another router. All registered listeners will be called. Unused. Not fully implemented.
        Specified by:
        reportAbuse in interface I2PSessionListener
        Specified by:
        reportAbuse in interface I2PSessionMuxedListener
        Parameters:
        session - session to report abuse to
        severity - how bad the abuse is