lokinet/llarp/transit_hop.cpp

#include <llarp/path.hpp>
#include "buffer.hpp"
#include "router.hpp"

namespace llarp
{
  bool
  TransitHop::Expired(llarp_time_t now) const
  {
    return now - started > lifetime;
  }

  TransitHopInfo::TransitHopInfo(const TransitHopInfo& other)
      : upstream(other.upstream)
      , downstream(other.downstream)
  {
  }

  TransitHopInfo::TransitHopInfo(const RouterID& down,
                                 const LR_CommitRecord& record)
      : upstream(record.nextHop), downstream(down)
  {
  }

  TransitHop::TransitHop(const TransitHop& other)
      : info(other.info)
      , pathKey(other.pathKey)
      , started(other.started)
      , lifetime(other.lifetime)
      , version(other.version)
  {
  }

  bool
  TransitHop::SendRoutingMessage(const llarp::routing::IMessage* msg,
                                 llarp_router* r)
  {
    byte_t tmp[MAX_LINK_MSG_SIZE / 2];
    auto buf = llarp::StackBuffer< decltype(tmp) >(tmp);
    if(!msg->BEncode(&buf))
    {
      llarp::Error("failed to encode routing message");
      return false;
    }
    TunnelNonce N;
    N.Randomize();
    // rewind
    buf.sz  = buf.cur - buf.base;
    buf.cur = buf.base;
    return HandleDownstream(buf, N, r);
  }

  bool
  TransitHop::HandleDownstream(llarp_buffer_t buf, const TunnelNonce& Y,
                               llarp_router* r)
  {
    RelayDownstreamMessage* msg = new RelayDownstreamMessage;
    msg->pathid                 = info.rxID;
    msg->Y                      = Y;

    r->crypto.xchacha20(buf, pathKey, Y);
    msg->X = buf;
    llarp::Info("relay ", msg->X.size(), " bytes downstream from ",
                info.upstream, " to ", info.downstream);
    return r->SendToOrQueue(info.downstream, msg);
  }

  bool
  TransitHop::HandleUpstream(llarp_buffer_t buf, const TunnelNonce& Y,
                             llarp_router* r)
  {
    RelayUpstreamMessage* msg = new RelayUpstreamMessage;
    msg->pathid               = info.txID;
    msg->Y                    = Y;

    r->crypto.xchacha20(buf, pathKey, Y);
    msg->X = buf;
    llarp::Info("relay ", msg->X.size(), " bytes upstream from ",
                info.downstream, " to ", info.upstream);
    return r->SendToOrQueue(info.upstream, msg);
  }

}  // namespace llarp