DNS-message.hpp

   1 #ifndef DNS_MESSAGE_DOT_HPP
   2 #define DNS_MESSAGE_DOT_HPP
   3
   4 #include <limits>
   5 #include <memory>
   6
   7 #include "DNS-rrs.hpp"
   8
   9 #include "iobuffer.hpp"
  10
  11 #include <glog/logging.h>
  12
  13 namespace Config {
  14 auto constexpr max_udp_sz{uint16_t(4 * 1024)};
  15 } // namespace Config
  16
  17 namespace DNS {
  18
  19 class message {
  20 public:
  21   using octet       = unsigned char;
  22   using container_t = iobuffer<octet>;
  23
  24   message() = default;
  25
  26   explicit message(container_t::size_type sz)
  27     : buf_(sz)
  28   {
  29     CHECK_LE(sz, std::numeric_limits<uint16_t>::max());
  30   }
  31
  32   explicit message(container_t&& buf)
  33     : buf_{buf}
  34   {
  35     CHECK_LE(buf.size(), std::numeric_limits<uint16_t>::max());
  36   }
  37
  38   operator std::span<octet>() { return {buf_.data(), buf_.size()}; }
  39   operator std::span<octet const>() const { return {buf_.data(), buf_.size()}; }
  40
  41   uint16_t id() const;
  42
  43   static size_t min_sz();
  44
  45 private:
  46   container_t buf_;
  47 };
  48
  49 DNS::message
  50 create_question(char const* name, DNS::RR_type type, uint16_t cls, uint16_t id);
  51
  52 void check_answer(bool&          nx_domain,
  53                   bool&          bogus_or_indeterminate,
  54                   uint16_t&      rcode,
  55                   uint16_t&      extended_rcode,
  56                   bool&          truncation,
  57                   bool&          authentic_data,
  58                   bool&          has_record,
  59                   message const& question,
  60                   message const& answer,
  61                   RR_type        type,
  62                   char const*    name);
  63
  64 RR_collection get_records(message const& pkt, bool& bogus_or_indeterminate);
  65
  66 } // namespace DNS
  67
  68 #endif // DNS_MESSAGE_DOT_HPP