text: /*
   * Copyright (c) 2020, the SerenityOS developers.
   *
   * SPDX-License-Identifier: BSD-2-Clause
   */
  
  #pragma once
  
  #include "DHCPv4.h"
  #include <AK/HashMap.h>
  #include <AK/OwnPtr.h>
  #include <AK/Result.h>
  #include <AK/String.h>
  #include <AK/Vector.h>
  #include <LibCore/UDPServer.h>
  #include <net/if.h>
  #include <net/route.h>
  #include <sys/ioctl.h>
  #include <sys/socket.h>
  
  struct InterfaceDescriptor {
      String ifname;
      MACAddress mac_address;
      IPv4Address current_ip_address;
  };
  
  struct DHCPv4Transaction {
      DHCPv4Transaction(InterfaceDescriptor ifname)
          : interface(ifname)
      {
      }
  
      InterfaceDescriptor interface;
      bool accepted_offer { false };
      bool has_ip { false };
      u32 offered_lease_time { 0 };
  };
  
  class DHCPv4Client final : public Core::Object {
      C_OBJECT(DHCPv4Client)
  
  public:
      virtual ~DHCPv4Client() override;
  
      void dhcp_discover(const InterfaceDescriptor& ifname);
      void dhcp_request(DHCPv4Transaction& transaction, const DHCPv4Packet& packet);
  
      void process_incoming(const DHCPv4Packet& packet);
  
      bool id_is_registered(u32 id) { return m_ongoing_transactions.contains(id); }
  
      struct Interfaces {
          Vector<InterfaceDescriptor> ready;
          Vector<InterfaceDescriptor> not_ready;
      };
      static Result<Interfaces, String> get_discoverable_interfaces();
  
  private:
      explicit DHCPv4Client();
  
      void try_discover_ifs();
  
      HashMap<u32, OwnPtr<DHCPv4Transaction>> m_ongoing_transactions;
      RefPtr<Core::UDPServer> m_server;
      RefPtr<Core::Timer> m_check_timer;
      int m_max_timer_backoff_interval { 600000 }; // 10 minutes
  
      void handle_offer(const DHCPv4Packet&, const ParsedDHCPv4Options&);
      void handle_ack(const DHCPv4Packet&, const ParsedDHCPv4Options&);
      void handle_nak(const DHCPv4Packet&, const ParsedDHCPv4Options&);
  };
  