arp.rflx

with Ethernet;
with IPv4;

package ARP is

   -- RFC 826

   type Hardware_Address_Space is
      (HAS_ETHERNET =>   1,
       HAS_HW_EXP1  =>  36,
       HAS_HW_EXP2  => 256)
   with Size => 16;

   type Opcode is (OP_REQUEST => 1, OP_REPLY => 2) with Size => 16;

   type Address_Length is mod 2**8;

   type Packet_IPv4 is
      message
         --  Hardware address space
         Hrd : Hardware_Address_Space
            then Pro if Hrd = HAS_ETHERNET;
         --  Protocol address space
         Pro : Ethernet::Ether_Type
            then Hln if Pro = Ethernet::ET_IPV4;
         --  Byte length of each hardware address
         Hln : Address_Length
            --  ISSUE: Componolit/RecordFlux#559
            --  then pln if Hln = Ethernet::Address'Size / 8;
            then Pln if Hln = 6;
         --  Byte length of each protocol address
         Pln : Address_Length
            --  ISSUE: Componolit/RecordFlux#559
            --  then Op if Pln = IPv4::Address'Size / 8;
            then Op if Pln = 4;
         Op  : Opcode;
         --  Hardware address of sender of this packet
         Sha : Ethernet::Address;
         --  Protocol address of sender of this packet
         Spa : IPv4::Address;
         --  Hardware address of target of this packet
         Tha : Ethernet::Address;
         --  Protocol address of target
         Tpa : IPv4::Address;
      end message;

end ARP;