java.lang.Object
org.klomp.snark.ExtensionHandler
abstract class ExtensionHandlerextends Object
REF: BEP 10 Extension Protocol.

  • Field Summary

    Modifier and Type
    Field
    Description
    private static final byte[]
    COMMENTS_FILTER
    Filter saying comment requests are not wanted.
    private static final int
    HASH_LENGTH
    Length of the piece hashes, in bytes.
    static final int
    ID_COMMENT
    Comment extension message ID (4).
    static final int
    ID_DHT
    DHT extension message ID (3).
    static final int
    ID_HANDSHAKE
    Handshake extension message ID (0).
    static final int
    ID_LT_DONTHAVE
    BEP 54 lt_donthave extension message ID (5).
    static final int
    ID_METADATA
    Metadata extension message ID (1).
    static final int
    ID_PEX
    PEX extension message ID (2).
    private static final int
    MAX_METADATA_SIZE
    Pieces * SHA1 Hash length, + 25% extra for file names, bencoding overhead, etc.
    private static final int
    PARALLEL_REQUESTS
    Extension requests in flight per peer.
    static final String
    TYPE_COMMENT
    Comment extension type string, carried in the handshake's type map.
    private static final int
    TYPE_DATA
    Extension message carrying data.
    static final String
    TYPE_DHT
    Not using the option bit since the compact format is different.
    static final String
    TYPE_LT_DONTHAVE
    BEP 54 lt_donthave extension type string.
    static final String
    TYPE_METADATA
    Metadata extension type string.
    static final String
    TYPE_PEX
    Not ut_pex since the compact format is different.
    private static final int
    TYPE_REJECT
    Extension message refusing a request.
    private static final int
    TYPE_REQUEST
    Extension message asking for data.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ExtensionHandler()
    Constructor for subclasses, each of which handles one BEP 10 extension protocol.

  • Method Summary

    Modifier and Type
    Method
    Description
    static byte[]
    getHandshake(int metasize, boolean pexAndMetadata, boolean dht, boolean uploadOnly, boolean comment, String clientName)
    Creates a bencoded extension handshake message.
    private static void
    handleComment(Peer peer, PeerListener listener, byte[] bs, Log log)
    Handles an incoming comment request or response message.
    private static void
    handleDHT(Peer peer, PeerListener listener, byte[] bs, Log log)
    Handles an incoming DHT port message.
    private static void
    handleHandshake(Peer peer, PeerListener listener, byte[] bs, Log log)
    Handles an incoming extension handshake message.
    static void
    handleMessage(Peer peer, PeerListener listener, int id, byte[] bs)
    Handles an incoming extension message from a peer.
    private static void
    handleMetadata(Peer peer, PeerListener listener, byte[] bs, Log log)
    Handles an incoming metadata extension message (BEP 9).
    private static void
    handlePEX(Peer peer, PeerListener listener, byte[] bs, Log log)
    Handles an incoming PEX message.
    static void
    locked_sendComments(Peer peer, int num, CommentSet comments)
    Sends comments to a peer.
    static void
    sendCommentReq(Peer peer, int num)
    Sends a comment request to a peer.
    static void
    sendDHT(Peer peer, int qport, int rport)
    Sends DHT port numbers to a peer.
    static void
    sendDontHave(Peer peer, int piece)
    Send a BEP 54 lt_donthave message to a peer that advertised support: the piece is no longer available.
    private static void
    sendExtension(Peer peer, String type, byte[] payload)
    Send an extension message to a peer, looking up its message code for the given type in the handshake.
    private static void
    sendMessage(Peer peer, int type, int piece)
    Sends a metadata request or reject message to a peer.
    static void
    sendPEX(Peer peer, List<Peer> pList)
    Sends a PEX message with the given peer list.
    private static void
    sendPiece(Peer peer, int piece, byte[] data, int totalSize)
    Sends a metadata chunk data message to a peer.
    private static void
    sendRequest(Peer peer, int piece)
    Sends a metadata chunk request to a peer.

    Methods inherited from class Object

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

  • Field Details

    • ID_HANDSHAKE

      public static final int ID_HANDSHAKE
      Handshake extension message ID (0).
      See Also:

    • ID_METADATA

      public static final int ID_METADATA
      Metadata extension message ID (1).
      See Also:

    • TYPE_METADATA

      public static final String TYPE_METADATA
      Metadata extension type string.
      See Also:

    • ID_PEX

      public static final int ID_PEX
      PEX extension message ID (2).
      See Also:

    • TYPE_PEX

      public static final String TYPE_PEX
      Not ut_pex since the compact format is different.
      See Also:

    • ID_DHT

      public static final int ID_DHT
      DHT extension message ID (3).
      See Also:

    • TYPE_DHT

      public static final String TYPE_DHT
      Not using the option bit since the compact format is different.
      See Also:

    • ID_COMMENT

      public static final int ID_COMMENT
      Comment extension message ID (4).
      See Also:

    • TYPE_COMMENT

      public static final String TYPE_COMMENT
      Comment extension type string, carried in the handshake's type map.
      See Also:

    • ID_LT_DONTHAVE

      public static final int ID_LT_DONTHAVE
      BEP 54 lt_donthave extension message ID (5).
      See Also:

    • TYPE_LT_DONTHAVE

      public static final String TYPE_LT_DONTHAVE
      BEP 54 lt_donthave extension type string.
      See Also:

    • MAX_METADATA_SIZE

      private static final int MAX_METADATA_SIZE
      Pieces * SHA1 Hash length, + 25% extra for file names, bencoding overhead, etc.
      See Also:

    • PARALLEL_REQUESTS

      private static final int PARALLEL_REQUESTS
      Extension requests in flight per peer.
      See Also:

    • TYPE_REQUEST

      private static final int TYPE_REQUEST
      Extension message asking for data.
      See Also:

    • TYPE_DATA

      private static final int TYPE_DATA
      Extension message carrying data.
      See Also:

    • TYPE_REJECT

      private static final int TYPE_REJECT
      Extension message refusing a request.
      See Also:

    • HASH_LENGTH

      private static final int HASH_LENGTH
      Length of the piece hashes, in bytes.
      See Also:

    • COMMENTS_FILTER

      private static final byte[] COMMENTS_FILTER
      Filter saying comment requests are not wanted.

  • Constructor Details

    • ExtensionHandler

      ExtensionHandler()
      Constructor for subclasses, each of which handles one BEP 10 extension protocol.

  • Method Details

    • sendExtension

      private static void sendExtension(Peer peer, String type, byte[] payload)
      Send an extension message to a peer, looking up its message code for the given type in the handshake. Silently ignores peers that did not advertise the extension.
      Parameters:
      peer - the peer to send to
      type - the extension type name (TYPE_* constant)
      payload - the bencoded message payload

    • getHandshake

      public static byte[] getHandshake(int metasize, boolean pexAndMetadata, boolean dht, boolean uploadOnly, boolean comment, String clientName)
      Creates a bencoded extension handshake message.
      Parameters:
      metasize - the metadata size in bytes, or -1 if unknown
      pexAndMetadata - true to advertise PEX and metadata extensions
      dht - true to advertise DHT capability
      uploadOnly - true to advertise upload-only mode (BEP 21)
      comment - true to advertise ut_comment extension
      clientName - the "v" value, or null for the default "I2PSnark"
      Returns:
      bencoded outgoing handshake message

    • sendDontHave

      public static void sendDontHave(Peer peer, int piece)
      Send a BEP 54 lt_donthave message to a peer that advertised support: the piece is no longer available. The payload is the raw 4-byte piece index.
      Parameters:
      peer - the peer to send to
      piece - the piece index

    • handleMessage

      public static void handleMessage(Peer peer, PeerListener listener, int id, byte[] bs)
      Handles an incoming extension message from a peer.
      Parameters:
      peer - the peer the message arrived from
      listener - the peer listener for callbacks
      id - the extension message ID
      bs - the raw message bytes

    • handleHandshake

      private static void handleHandshake(Peer peer, PeerListener listener, byte[] bs, Log log)
      Handles an incoming extension handshake message.
      Parameters:
      peer - the peer the message arrived from
      listener - the peer listener for callbacks
      bs - the raw message bytes
      log - the logger instance

    • handleMetadata

      private static void handleMetadata(Peer peer, PeerListener listener, byte[] bs, Log log)
      Handles an incoming metadata extension message (BEP 9).
      Parameters:
      peer - the peer the message arrived from
      listener - the peer listener for callbacks
      bs - the raw message bytes
      log - the logger instance

    • sendRequest

      private static void sendRequest(Peer peer, int piece)
      Sends a metadata chunk request to a peer.
      Parameters:
      peer - the peer the message arrived from
      piece - the chunk number to request

    • sendMessage

      private static void sendMessage(Peer peer, int type, int piece)
      Sends a metadata request or reject message to a peer.
      Parameters:
      peer - the peer the message arrived from
      type - the message type (TYPE_REQUEST or TYPE_REJECT)
      piece - the chunk number

    • sendPiece

      private static void sendPiece(Peer peer, int piece, byte[] data, int totalSize)
      Sends a metadata chunk data message to a peer.
      Parameters:
      peer - the peer the message arrived from
      piece - the chunk number
      data - the chunk data bytes
      totalSize - the total metadata size

    • handlePEX

      private static void handlePEX(Peer peer, PeerListener listener, byte[] bs, Log log)
      Handles an incoming PEX message. Uses the "added" key as a single string of concatenated 32-byte peer hashes. added.f and dropped are unsupported.
      Parameters:
      peer - the peer the message arrived from
      listener - the peer listener for callbacks
      bs - the raw message bytes
      log - the logger instance

    • handleDHT

      private static void handleDHT(Peer peer, PeerListener listener, byte[] bs, Log log)
      Handles an incoming DHT port message.
      Parameters:
      peer - the peer the message arrived from
      listener - the peer listener for callbacks
      bs - the raw message bytes
      log - the logger instance

    • sendPEX

      public static void sendPEX(Peer peer, List<Peer> pList)
      Sends a PEX message with the given peer list. added.f and dropped are unsupported.
      Parameters:
      peer - the peer the message arrived from
      pList - non-null list of peers to share

    • sendDHT

      public static void sendDHT(Peer peer, int qport, int rport)
      Sends DHT port numbers to a peer.
      Parameters:
      peer - the peer the message arrived from
      qport - the query port
      rport - the response port

    • handleComment

      private static void handleComment(Peer peer, PeerListener listener, byte[] bs, Log log)
      Handles an incoming comment request or response message.
      Parameters:
      peer - the peer the message arrived from
      listener - the peer listener for callbacks
      bs - the raw message bytes
      log - the logger instance

    • sendCommentReq

      public static void sendCommentReq(Peer peer, int num)
      Sends a comment request to a peer.
      Parameters:
      peer - the peer the message arrived from
      num - the maximum number of comments to request

    • locked_sendComments

      public static void locked_sendComments(Peer peer, int num, CommentSet comments)
      Sends comments to a peer. Caller must synchronize on comments.
      Parameters:
      peer - the peer the message arrived from
      num - the maximum number of comments to send
      comments - non-null set of comments to send