lokinet/llarp/routing/message_parser.cpp

#include "message_parser.hpp"

#include <llarp/exit/exit_messages.hpp>
#include <llarp/messages/discard.hpp>
#include <llarp/path/path_types.hpp>
#include "dht_message.hpp"
#include "path_confirm_message.hpp"
#include "path_latency_message.hpp"
#include "path_transfer_message.hpp"
#include "transfer_traffic_message.hpp"
#include <llarp/util/mem.hpp>

namespace llarp::routing
{
  struct InboundMessageParser::MessageHolder
  {
    DataDiscardMessage D;
    PathLatencyMessage L;
    DHTMessage M;
    PathConfirmMessage P;
    PathTransferMessage T;
    service::ProtocolFrame H;
    TransferTrafficMessage I;
    GrantExitMessage G;
    RejectExitMessage J;
    ObtainExitMessage O;
    UpdateExitMessage U;
    CloseExitMessage C;
  };

  InboundMessageParser::InboundMessageParser() : m_Holder(std::make_unique<MessageHolder>())
  {}

  InboundMessageParser::~InboundMessageParser() = default;

  bool
  InboundMessageParser::operator()(llarp_buffer_t* buffer, llarp_buffer_t* key)
  {
    if (key == nullptr && firstKey)
    {
      // empty dict
      return false;
    }
    if (!key)
      return true;
    if (firstKey)
    {
      llarp_buffer_t strbuf;
      if (!(key->startswith("A")))
        return false;
      if (!bencode_read_string(buffer, &strbuf))
        return false;
      if (strbuf.sz != 1)
        return false;
      ourKey = *strbuf.cur;
      LogDebug("routing message '", std::string{ourKey, 1}, "'");
      switch (ourKey)
      {
        case 'D':
          msg = &m_Holder->D;
          break;
        case 'L':
          msg = &m_Holder->L;
          break;
        case 'M':
          msg = &m_Holder->M;
          break;
        case 'P':
          msg = &m_Holder->P;
          break;
        case 'T':
          msg = &m_Holder->T;
          break;
        case 'H':
          msg = &m_Holder->H;
          break;
        case 'I':
          msg = &m_Holder->I;
          break;
        case 'G':
          msg = &m_Holder->G;
          break;
        case 'J':
          msg = &m_Holder->J;
          break;
        case 'O':
          msg = &m_Holder->O;
          break;
        case 'U':
          msg = &m_Holder->U;
          break;
        case 'C':
          msg = &m_Holder->C;
          break;
        default:
          llarp::LogError("invalid routing message id: ", *strbuf.cur);
      }
      if (msg)
        msg->version = version;
      firstKey = false;
      return msg != nullptr;
    }

    return msg->DecodeKey(*key, buffer);
  }

  bool
  InboundMessageParser::ParseMessageBuffer(
      const llarp_buffer_t& buf,
      AbstractRoutingMessageHandler* h,
      const PathID_t& from,
      AbstractRouter* r)
  {
    bool result = false;
    msg = nullptr;
    firstKey = true;
    ManagedBuffer copiedBuf(buf);
    auto& copy = copiedBuf.underlying;
    uint64_t v = 0;
    if (BEncodeSeekDictVersion(v, &copy, 'V'))
    {
      version = v;
    }
    if (bencode_read_dict(*this, &copy))
    {
      msg->from = from;
      LogDebug("handle routing message ", msg->S, " from ", from);
      result = msg->HandleMessage(h, r);
      if (!result)
      {
        llarp::LogWarn("Failed to handle inbound routing message ", ourKey);
      }
    }
    else
    {
      llarp::LogError("read dict failed in routing layer");
      llarp::DumpBuffer<llarp_buffer_t, 128>(buf);
    }
    if (msg)
      msg->Clear();
    msg = nullptr;
    version = 0;
    return result;
  }
}  // namespace llarp::routing