dnsdist: Add documentation and a regression test for FFI functions

[thirdparty/pdns.git] / pdns / dnsdistdist / dnsdist-lua-ffi.hh

/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#pragma once

#include "dnsdist.hh"

extern "C" {
  typedef struct dnsdist_ffi_dnsquestion_t dnsdist_ffi_dnsquestion_t;

  typedef struct dnsdist_ednsoption {
    uint16_t    optionCode;
    uint16_t    len;
    const void* data;
  } dnsdist_ednsoption_t;

  typedef struct dnsdist_http_header {
    const char* name;
    const char* value;
  } dnsdist_http_header_t;

  void dnsdist_ffi_dnsquestion_get_localaddr(const dnsdist_ffi_dnsquestion_t* dq, const void** addr, size_t* addrSize) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_get_remoteaddr(const dnsdist_ffi_dnsquestion_t* dq, const void** addr, size_t* addrSize) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_get_qname_raw(const dnsdist_ffi_dnsquestion_t* dq, const char** qname, size_t* qnameSize) __attribute__ ((visibility ("default")));
  uint16_t dnsdist_ffi_dnsquestion_get_qtype(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  uint16_t dnsdist_ffi_dnsquestion_get_qclass(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  int dnsdist_ffi_dnsquestion_get_rcode(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  void* dnsdist_ffi_dnsquestion_get_header(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  uint16_t dnsdist_ffi_dnsquestion_get_len(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  size_t dnsdist_ffi_dnsquestion_get_size(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  uint8_t dnsdist_ffi_dnsquestion_get_opcode(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_get_tcp(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_get_skip_cache(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_get_use_ecs(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_get_add_xpf(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_get_ecs_override(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  uint16_t dnsdist_ffi_dnsquestion_get_ecs_prefix_length(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_is_temp_failure_ttl_set(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  uint32_t dnsdist_ffi_dnsquestion_get_temp_failure_ttl(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  bool dnsdist_ffi_dnsquestion_get_do(const dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_get_sni(const dnsdist_ffi_dnsquestion_t* dq, const char** sni, size_t* sniSize) __attribute__ ((visibility ("default")));
  const char* dnsdist_ffi_dnsquestion_get_tag(const dnsdist_ffi_dnsquestion_t* dq, const char* label) __attribute__ ((visibility ("default")));
  const char* dnsdist_ffi_dnsquestion_get_http_path(dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  const char* dnsdist_ffi_dnsquestion_get_http_query_string(dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  const char* dnsdist_ffi_dnsquestion_get_http_host(dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));
  const char* dnsdist_ffi_dnsquestion_get_http_scheme(dnsdist_ffi_dnsquestion_t* dq) __attribute__ ((visibility ("default")));

  // returns the length of the resulting 'out' array. 'out' is not set if the length is 0
  size_t dnsdist_ffi_dnsquestion_get_edns_options(dnsdist_ffi_dnsquestion_t* ref, const dnsdist_ednsoption_t** out) __attribute__ ((visibility ("default")));
  size_t dnsdist_ffi_dnsquestion_get_http_headers(dnsdist_ffi_dnsquestion_t* ref, const dnsdist_http_header_t** out) __attribute__ ((visibility ("default")));

  void dnsdist_ffi_dnsquestion_set_result(dnsdist_ffi_dnsquestion_t* dq, const char* str, size_t strSize) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_rcode(dnsdist_ffi_dnsquestion_t* dq, int rcode) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_len(dnsdist_ffi_dnsquestion_t* dq, uint16_t len) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_skip_cache(dnsdist_ffi_dnsquestion_t* dq, bool skipCache) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_use_ecs(dnsdist_ffi_dnsquestion_t* dq, bool useECS) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_ecs_override(dnsdist_ffi_dnsquestion_t* dq, bool ecsOverride) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_ecs_prefix_length(dnsdist_ffi_dnsquestion_t* dq, uint16_t ecsPrefixLength) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_temp_failure_ttl(dnsdist_ffi_dnsquestion_t* dq, uint32_t tempFailureTTL) __attribute__ ((visibility ("default")));
  void dnsdist_ffi_dnsquestion_set_tag(dnsdist_ffi_dnsquestion_t* dq, const char* label, const char* value) __attribute__ ((visibility ("default")));

  void dnsdist_ffi_dnsquestion_set_http_response(dnsdist_ffi_dnsquestion_t* dq, uint16_t statusCode, const char* body, const char* contentType) __attribute__ ((visibility ("default")));
}

// dnsdist_ffi_dnsquestion_t is a lightuserdata
template<>
struct LuaContext::Pusher<dnsdist_ffi_dnsquestion_t*> {
    static const int minSize = 1;
    static const int maxSize = 1;

    static PushedObject push(lua_State* state, dnsdist_ffi_dnsquestion_t* ptr) noexcept {
        lua_pushlightuserdata(state, ptr);
        return PushedObject{state, 1};
    }
};

struct dnsdist_ffi_dnsquestion_t
{
  dnsdist_ffi_dnsquestion_t(DNSQuestion* dq_): dq(dq_)
  {
  }

  DNSQuestion* dq{nullptr};
  std::vector<dnsdist_ednsoption_t> ednsOptionsVect;
  std::vector<dnsdist_http_header> httpHeadersVect;
  std::unordered_map<std::string, std::string> httpHeaders;
  boost::optional<std::string> result{boost::none};
  boost::optional<std::string> httpPath{boost::none};
  boost::optional<std::string> httpQueryString{boost::none};
  boost::optional<std::string> httpHost{boost::none};
  boost::optional<std::string> httpScheme{boost::none};
};