Package net.i2p.router.tunnel

Class TunnelDispatcher

  • All Implemented Interfaces:
    Service
    public class TunnelDispatcher
extends Object
implements Service
    Handle the actual processing and forwarding of messages through the various tunnels. 
      For each type of tunnel, it creates a chain of handlers, as follows:

  Following tunnels are created by us:

    Outbound Gateway > 0 hops:
       PumpedTunnelGateway
         BatchedRouterPreprocessor -> OutboundSender -> OutboundReceiver -> OutNetMessagePool

    Outbound zero-hop Gateway+Endpoint:
       TunnelGatewayZeroHop
         OutboundMessageDistributor -> OutNetMessagePool

    Inbound Endpoint > 0 hops:
       TunnelParticipant
        RouterFragmentHandler ->  InboundEndpointProcessor -> InboundMessageDistributor -> InNetMessagePool

    Inbound zero-hop Gateway+Endpoint:
       TunnelGatewayZeroHop
         InboundMessageDistributor -> InNetMessagePool


  Following tunnels are NOT created by us:

    Participant (not gateway or endpoint)
       TunnelParticipant
         HopProcessor -> OutNetMessagePool

    Outbound Endpoint > 0 hops:
       OutboundTunnelEndpoint
         RouterFragmentHandler -> HopProcessor -> OutboundMessageDistributor -> OutNetMessagePool

    Inbound Gateway > 0 hops:
       ThrottledPumpedTunnelGateway
         BatchedRouterPreprocessor -> InboundSender -> InboundGatewayReceiver -> OutNetMessagePool

    • Constructor Detail

      • TunnelDispatcher

        public TunnelDispatcher​(RouterContext ctx)
        Creates a new instance of TunnelDispatcher

    • Method Detail

      • joinOutbound

        public boolean joinOutbound​(TunnelCreatorConfig cfg)
        We are the outbound gateway - we created this tunnel
        Returns:
        success; false if Tunnel ID is a duplicate

      • joinInbound

        public boolean joinInbound​(TunnelCreatorConfig cfg)
        We are the inbound endpoint - we created this tunnel
        Returns:
        success; false if Tunnel ID is a duplicate

      • joinParticipant

        public boolean joinParticipant​(HopConfig cfg)
        We are a participant in this tunnel, but not as the endpoint or gateway
        Returns:
        success; false if Tunnel ID is a duplicate

      • joinOutboundEndpoint

        public boolean joinOutboundEndpoint​(HopConfig cfg)
        We are the outbound endpoint in this tunnel, and did not create it
        Returns:
        success; false if Tunnel ID is a duplicate

      • joinInboundGateway

        public boolean joinInboundGateway​(HopConfig cfg)
        We are the inbound gateway in this tunnel, and did not create it
        Returns:
        success; false if Tunnel ID is a duplicate

      • getParticipatingCount

        public int getParticipatingCount()

      • getNewOBGWID

        public TunnelId getNewOBGWID()
        Get a new random send tunnel ID that isn't a dup. Note that we do not keep track of IDs for pending builds so this does not fully prevent joinOutbound() from failing later.
        Since:
        0.9.5

      • getNewIBEPID

        public TunnelId getNewIBEPID()
        Get a new random receive tunnel ID that isn't a dup. Not for zero hop tunnels. Note that we do not keep track of IDs for pending builds so this does not fully prevent joinInbound() from failing later.
        Since:
        0.9.5

      • getNewIBZeroHopID

        public TunnelId getNewIBZeroHopID()
        Get a new random receive tunnel ID that isn't a dup. For zero hop tunnels only. Note that we do not keep track of IDs for pending builds so this does not fully prevent joinInbound() from failing later.
        Since:
        0.9.5

      • getLastParticipatingExpiration

        public long getLastParticipatingExpiration()
        what is the date/time on which the last non-locally-created tunnel expires?

      • remove

        public void remove​(TunnelCreatorConfig cfg)
        We no longer want to participate in this tunnel that we created

      • remove

        public void remove​(HopConfig cfg)
        No longer participate in the tunnel that someone asked us to be a member of

      • dispatch

        public void dispatch​(TunnelDataMessage msg,
                     Hash recvFrom)
        We are participating in a tunnel (perhaps we're even the endpoint), so take the message and do what it says. If there are later hops, that means encrypt a layer and forward it on. If there aren't later hops, how we handle it depends upon whether we created it or not. If we didn't, simply honor the instructions. If we did, unwrap all the layers of encryption and honor those instructions (within reason).

      • dispatch

        public void dispatch​(TunnelGatewayMessage msg)
        We are the inbound tunnel gateway, so encrypt it as necessary and forward it on.

      • dispatchOutbound

        public void dispatchOutbound​(I2NPMessage msg,
                             TunnelId outboundTunnel,
                             Hash targetPeer)
        We are the outbound tunnel gateway (we created it), so wrap up this message with instructions to be forwarded to the targetPeer when it reaches the endpoint.
        Parameters:
        msg - raw message to deliver to the target peer
        outboundTunnel - tunnel to send the message out, or null for direct
        targetPeer - peer to receive the message

      • dispatchOutbound

        public void dispatchOutbound​(I2NPMessage msg,
                             TunnelId outboundTunnel,
                             TunnelId targetTunnel,
                             Hash targetPeer)
        We are the outbound tunnel gateway (we created it), so wrap up this message with instructions to be forwarded to the targetTunnel on the targetPeer when it reaches the endpoint.
        Parameters:
        msg - raw message to deliver to the targetTunnel on the targetPeer
        outboundTunnel - tunnel to send the message out
        targetTunnel - tunnel on the targetPeer to deliver the message to, or null for direct
        targetPeer - gateway to the tunnel to receive the message

      • listParticipatingTunnels

        public List<HopConfig> listParticipatingTunnels()
        Only for console TunnelRenderer.
        Returns:
        a copy

      • updateParticipatingStats

        public void updateParticipatingStats​(int ms)
        Generate a current estimate of usage per-participating-tunnel lifetime. The router code calls this every 'ms' millisecs. This is better than waiting until the tunnel expires to update the rate, as we want this to be current because it's an important part of the throttle code. Stay a little conservative by taking the counts only for tunnels 1-10m old and computing the average from that.

      • shouldDropParticipatingMessage

        public boolean shouldDropParticipatingMessage​(TunnelDispatcher.Location loc,
                                              int type,
                                              int length)
        Implement random early discard (RED) to enforce the share bandwidth limit. For now, this does not enforce the available bandwidth, we leave that to Throttle. This is similar to the code in ../RouterThrottleImpl.java We drop in proportion to how far over the limit we are. Perhaps an exponential function would be better? The drop probability is adjusted for the size of the message. At this stage, participants and IBGWs see a standard 1024 byte message. OBEPs however may see a wide variety of sizes. Network-wise, it's most efficient to drop OBEP messages, because they are unfragmented and we know their size. Therefore we drop the big ones and we drop a single wrapped I2CP message, not a fragment of one or more messages. Also, the OBEP is the earliest identifiable hop in the message's path (a plain participant could be earlier or later, but on average is later)
        Parameters:
        loc - message hop location
        type - I2NP message type
        length - the length of the message

      • startup

        public void startup()
        startup
        Specified by:
        startup in interface Service

      • getShareBandwidth

        public static int getShareBandwidth​(RouterContext ctx)
        Returns:
        in KBps

      • shutdown

        public void shutdown()
        Description copied from interface: Service
        Instruct the service that the router is shutting down and that it should do whatever is necessary to go down gracefully. It should not depend on other components at this point. This call DOES block.
        Specified by:
        shutdown in interface Service

      • restart

        public void restart()
        Description copied from interface: Service
        Perform a soft restart.
        Specified by:
        restart in interface Service