lokinet/llarp/service/outbound_context.hpp

#pragma once

#include <llarp/path/pathbuilder.hpp>
#include <llarp/service/convotag.hpp>
#include <llarp/util/status.hpp>

#include <unordered_map>
#include <unordered_set>

namespace llarp::service
{
  struct AsyncKeyExchange;
  struct Endpoint;

  /// context needed to initiate an outbound hidden service session
  struct OutboundContext : public llarp::path::Builder,
                           public std::enable_shared_from_this<OutboundContext>
  {
   private:
    Endpoint& ep;

    IntroSet current_intro;
    Introduction next_intro;

    const dht::Key_t location;
    const Address addr;

    ServiceInfo remote_identity;
    Introduction remote_intro;

    ConvoTag current_tag;
    
    uint64_t update_introset_tx = 0;
    uint16_t lookup_fails = 0;
    uint16_t build_fails = 0;
    
    bool got_inbound_traffic = false;
    bool generated_intro = false;
    bool sent_intro = false;
    bool marked_bad = false;
    
    const std::chrono::milliseconds created_at;
    std::chrono::milliseconds last_send = 0ms;
    std::chrono::milliseconds send_timeout = path::BUILD_TIMEOUT;
    std::chrono::milliseconds connect_timeout = send_timeout * 2;
    std::chrono::milliseconds last_shift = 0ms;
    std::chrono::milliseconds last_inbound_traffic = 0ms;
    std::chrono::milliseconds last_introset_update = 0ms;
    std::chrono::milliseconds last_keep_alive = 0ms;

   public:
    OutboundContext(const IntroSet& introSet, Endpoint* parent);
    
    ~OutboundContext() override;

    void
    encrypt_and_send(std::string buf);

    void
    Tick(std::chrono::milliseconds now) override;

    util::StatusObject
    ExtractStatus() const;

    void
    BlacklistSNode(const RouterID) override{};

    path::PathSet_ptr
    GetSelf() override
    {
      return shared_from_this();
    }

    std::weak_ptr<path::PathSet>
    GetWeak() override
    {
      return weak_from_this();
    }

    Address
    Addr() const;

    bool
    Stop() override;

    void
    HandlePathDied(path::Path_ptr p) override;

    /// set to true if we are updating the remote introset right now
    bool updatingIntroSet;

    /// update the current selected intro to be a new best introduction
    /// return true if we have changed intros
    bool
    ShiftIntroduction(bool rebuild = true);

    /// shift the intro off the current router it is using
    void
    ShiftIntroRouter(const RouterID remote);

    /// return true if we are ready to send
    bool
    ReadyToSend() const;

    /// for exits
    void
    send_packet_to_remote(std::string buf) override;

    bool
    ShouldBuildMore(std::chrono::milliseconds now) const override;

    /// pump internal state
    /// return true to mark as dead
    bool
    Pump(std::chrono::milliseconds now);

    /// return true if it's safe to remove ourselves
    bool
    IsDone(std::chrono::milliseconds now) const;

    bool
    CheckPathIsDead(path::Path_ptr p, std::chrono::milliseconds dlt);

    void
    AsyncGenIntro(const llarp_buffer_t& payload, ProtocolType t);

    /// issues a lookup to find the current intro set of the remote service
    void
    UpdateIntroSet();

    void
    HandlePathBuilt(path::Path_ptr path) override;

    void
    HandlePathBuildTimeout(path::Path_ptr path) override;

    void
    HandlePathBuildFailedAt(path::Path_ptr path, RouterID hop) override;

    std::optional<std::vector<RouterContact>>
    GetHopsForBuild() override;

    std::string
    Name() const override;

    void
    KeepAlive();

    bool
    ShouldKeepAlive(std::chrono::milliseconds now) const;

    const IntroSet&
    GetCurrentIntroSet() const
    {
      return current_intro;
    }

    std::chrono::milliseconds
    RTT() const;

    bool
    OnIntroSetUpdate(
        const Address& addr,
        std::optional<IntroSet> i,
        const RouterID& endpoint,
        std::chrono::milliseconds,
        uint64_t relayOrder);

   private:
    /// swap remoteIntro with next intro
    void
    swap_intros();
  };
}  // namespace llarp::service