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
  23   using container_t = iobuffer<octet>;
  24
  25   message() = default;
  26
  27   explicit message(container_t::size_type sz)
  28     : bfr_(sz)
  29   {
  30     CHECK_LE(sz, std::numeric_limits<uint16_t>::max());
  31   }
  32
  33   explicit message(container_t&& bfr)
  34     : bfr_{std::move(bfr)}
  35   {
  36     CHECK_LE(size(), std::numeric_limits<uint16_t>::max());
  37   }
  38
  39   uint16_t size() const { return bfr_.size(); }
  40
  41   auto begin() const { return bfr_.data(); }
  42   auto end() const { return bfr_.data() + bfr_.size(); }
  43
  44   uint16_t id() const;
  45
  46 private:
  47   container_t bfr_;
  48 };
  49
  50 inline auto begin(message const& pkt) { return pkt.begin(); }
  51 inline auto end(message const& pkt) { return pkt.end(); }
  52 inline auto size(message const& pkt) { return pkt.size(); }
  53
  54 size_t min_udp_sz();
  55
  56 DNS::message
  57 create_question(char const* name, DNS::RR_type type, uint16_t cls, uint16_t id);
  58
  59 void check_answer(bool&          nx_domain,
  60                   bool&          bogus_or_indeterminate,
  61                   uint16_t&      rcode,
  62                   uint16_t&      extended_rcode,
  63                   bool&          authentic_data,
  64                   bool&          has_record,
  65                   message const& question,
  66                   message const& answer,
  67                   RR_type        type,
  68                   char const*    name);
  69
  70 RR_collection get_records(message const& pkt, bool& bogus_or_indeterminate);
  71
  72 } // namespace DNS
  73
  74 #endif // DNS_MESSAGE_DOT_HPP