lokinet/llarp/handlers/exit.hpp

#pragma once

#include "tun.hpp"

#include <llarp/dns/server.hpp>
#include <llarp/exit/endpoint.hpp>

#include <unordered_map>

namespace llarp
{
  struct Router;
  namespace handlers
  {
    struct ExitEndpoint : public dns::Resolver_Base, public EndpointBase
    {
      int
      Rank() const override
      {
        return 0;
      };

      std::string_view
      ResolverName() const override
      {
        return "snode";
      }

      bool
      MaybeHookDNS(
          std::shared_ptr<dns::PacketSource_Base> source,
          const dns::Message& query,
          const SockAddr& to,
          const SockAddr& from) override;

      ExitEndpoint(std::string name, Router* r);
      ~ExitEndpoint() override;

      std::optional<AddressVariant_t>
      GetEndpointWithConvoTag(service::ConvoTag tag) const override;

      std::optional<service::ConvoTag>
      GetBestConvoTagFor(AddressVariant_t addr) const override;

      bool
      EnsurePathTo(
          AddressVariant_t addr,
          std::function<void(std::optional<service::ConvoTag>)> hook,
          llarp_time_t timeout) override;

      void
      lookup_name(std::string name, std::function<void(oxen::quic::message)> func) override;

      const EventLoop_ptr&
      Loop() override;

      std::unordered_set<EndpointBase::AddressVariant_t>
      AllRemoteEndpoints() const override;

      void
      SRVRecordsChanged() override;

      void MarkAddressOutbound(service::Address) override{};

      bool
      send_to(service::ConvoTag tag, std::string payload) override;

      void
      Tick(llarp_time_t now);

      void
      Configure(const NetworkConfig& networkConfig, const DnsConfig& dnsConfig);

      std::string
      Name() const;

      bool
      VisitEndpointsFor(const PubKey& pk, std::function<bool(exit::Endpoint* const)> visit) const;

      util::StatusObject
      ExtractStatus() const;

      bool
      SupportsV6() const;

      bool
      ShouldHookDNSMessage(const dns::Message& msg) const;

      bool
      HandleHookedDNSMessage(dns::Message msg, std::function<void(dns::Message)>);

      void
      LookupServiceAsync(
          std::string name,
          std::string service,
          std::function<void(std::vector<dns::SRVData>)> handler) override;

      bool
      AllocateNewExit(const PubKey pk, const PathID_t& path, bool permitInternet);

      exit::Endpoint*
      FindEndpointByPath(const PathID_t& path);

      exit::Endpoint*
      FindEndpointByIP(huint32_t ip);

      bool
      UpdateEndpointPath(const PubKey& remote, const PathID_t& next);

      /// handle ip packet from outside
      void
      OnInetPacket(net::IPPacket buf);

      Router*
      GetRouter();

      llarp_time_t
      Now() const;

      template <typename Stats>
      void
      CalculateTrafficStats(Stats& stats)
      {
        for (auto& [pubkey, endpoint] : active_exits)
        {
          stats[pubkey].first += endpoint->TxRate();
          stats[pubkey].second += endpoint->RxRate();
        }
      }

      /// DO NOT CALL ME
      void
      DelEndpointInfo(const PathID_t& path);

      /// DO NOT CALL ME
      void
      RemoveExit(const exit::Endpoint* ep);

      bool
      QueueOutboundTraffic(net::IPPacket pkt);

      AddressVariant_t
      LocalAddress() const override;

      std::optional<SendStat>
      GetStatFor(AddressVariant_t remote) const override;

      /// sets up networking and starts traffic
      bool
      Start();

      bool
      Stop();

      bool
      ShouldRemove() const;

      bool
      HasLocalMappedAddrFor(const PubKey& pk) const;

      huint128_t
      GetIfAddr() const;

      void
      Flush();

      link::TunnelManager*
      GetQUICTunnel() override;

      huint128_t
      GetIPForIdent(const PubKey pk);
      /// async obtain snode session and call callback when it's ready to send
      void
      ObtainSNodeSession(const RouterID& rid, exit::SessionReadyFunc obtain_cb);

     private:
      huint128_t
      AllocateNewAddress();

      /// obtain ip for service node session, creates a new session if one does
      /// not existing already
      huint128_t
      ObtainServiceNodeIP(const RouterID& router);

      bool
      QueueSNodePacket(const llarp_buffer_t& buf, huint128_t from);

      void
      MarkIPActive(huint128_t ip);

      void
      KickIdentOffExit(const PubKey& pk);

      Router* router;
      std::shared_ptr<dns::Server> resolver;
      bool should_init_tun;
      std::string name;
      bool permit_exit;
      std::unordered_map<PathID_t, PubKey> paths;

      std::unordered_map<PubKey, exit::Endpoint*> chosen_exits;

      std::unordered_multimap<PubKey, std::unique_ptr<exit::Endpoint>> active_exits;

      std::unordered_map<PubKey, huint128_t> key_to_IP;

      using SNodes_t = std::set<PubKey>;
      /// set of pubkeys we treat as snodes
      SNodes_t snode_keys;

      using SNodeSessions_t = std::unordered_map<RouterID, std::shared_ptr<exit::SNodeSession>>;
      /// snode sessions we are talking to directly
      SNodeSessions_t snode_sessions;

      std::unordered_map<huint128_t, PubKey> ip_to_key;

      huint128_t if_addr;
      huint128_t highest_addr;

      huint128_t next_addr;
      IPRange ip_range;
      std::string if_name;

      std::unordered_map<huint128_t, llarp_time_t> ip_activity;

      std::shared_ptr<vpn::NetworkInterface> if_net;

      SockAddr resolver_addr;
      std::vector<SockAddr> upstream_resolvers;

      // std::shared_ptr<link::TunnelManager> tunnel_manager;

      using PacketQueue_t = std::
          priority_queue<net::IPPacket, std::vector<net::IPPacket>, net::IPPacket::CompareOrder>;

      /// internet to llarp packet queue
      PacketQueue_t inet_to_network;
      bool use_ipv6;
      DnsConfig dns_conf;
    };
  }  // namespace handlers
}  // namespace llarp