lokinet/include/llarp/handlers/tun.hpp

#ifndef LLARP_HANDLERS_TUN_HPP
#define LLARP_HANDLERS_TUN_HPP
#include <llarp/ev.h>
#include <llarp/codel.hpp>
#include <llarp/ip.hpp>
#include <llarp/service/endpoint.hpp>
#include <llarp/threading.hpp>

namespace llarp
{
  namespace handlers
  {
    static const int DefaultTunNetmask    = 16;
    static const char DefaultTunIfname[]  = "lokinet0";
    static const char DefaultTunDstAddr[] = "10.10.0.1";
    static const char DefaultTunSrcAddr[] = "10.10.0.2";

    struct TunEndpoint : public service::Endpoint
    {
      TunEndpoint(const std::string& nickname, llarp_router* r);
      ~TunEndpoint();

      bool
      SetOption(const std::string& k, const std::string& v);

      void
      Tick(llarp_time_t now);

      void
      TickTun(llarp_time_t now);

      bool
      MapAddress(const service::Address& remote, uint32_t ip);

      bool
      Start();

      /// set up tun interface, blocking
      bool
      SetupTun();

      /// overrides Endpoint
      bool
      SetupNetworking();

      /// extends Endpoint
      /// handle inbound traffic
      bool
      HandleDataMessage(const PathID_t& src, service::ProtocolMessage* msg);

#ifndef _MINGW32_NO_THREADS
      /// overrides Endpount
      bool
      IsolationFailed()
      {
        m_TunSetupResult.set_value(false);
        return false;
      }
#endif

      llarp_tun_io tunif;

      /// called before writing to tun interface
      static void
      tunifBeforeWrite(llarp_tun_io* t);

      /// handle user to network send buffer flush
      /// called in router logic thread
      static void
      handleNetSend(void*);

      /// called every time we wish to read a packet from the tun interface
      static void
      tunifRecvPkt(llarp_tun_io* t, const void* pkt, ssize_t sz);

      /// called in the endpoint logic thread
      static void
      handleTickTun(void* u);

     protected:
      typedef llarp::util::CoDelQueue<
          net::IPv4Packet, net::IPv4Packet::GetTime, net::IPv4Packet::PutTime,
          net::IPv4Packet::CompareOrder >
          PacketQueue_t;
      /// queue for sending packets over the network from us
      PacketQueue_t m_UserToNetworkPktQueue;
      /// queue for sending packets to user from network
      PacketQueue_t m_NetworkToUserPktQueue;
      /// return true if we have a remote loki address for this ip address
      bool
      HasRemoteForIP(const uint32_t& ipv4) const;
      /// get ip address for service address unconditionally
      uint32_t
      ObtainIPForAddr(const service::Address& addr);

      /// mark this address as active
      void
      MarkIPActive(uint32_t ip);

      /// mark this address as active forever
      void
      MarkIPActiveForever(uint32_t ip);

      void
      FlushSend();

     private:
#ifndef _MINGW32_NO_THREADS
      /// handles setup, given value true on success and false on failure to set
      /// up interface
      std::promise< bool > m_TunSetupResult;
#endif
      /// maps ip to service address
      std::unordered_map< uint32_t, service::Address > m_IPToAddr;
      /// maps service address to ip
      std::unordered_map< service::Address, uint32_t, service::Address::Hash >
          m_AddrToIP;
      /// maps ip address to timestamp last active
      std::unordered_map< uint32_t, llarp_time_t > m_IPActivity;
      /// our ip address
      uint32_t m_OurIP;
      /// next ip address to allocate
      uint32_t m_NextIP;
      /// highest ip address to allocate
      uint32_t m_MaxIP;
    };
  }  // namespace handlers
}  // namespace llarp

#endif