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lokinet/llarp/dnsd.hpp
2019-02-03 00:48:10 +00:00

124 lines
3.4 KiB
C++

#ifndef LLARP_DNSD_HPP
#define LLARP_DNSD_HPP
#include <dns.hpp> // question and dnsc
#include <dnsc.hpp>
#include <ev/ev.h> // for sockaadr
#include <string>
//
// Input structures/functions:
//
// fwd declaration
struct dnsd_context;
/// sendto hook functor
using sendto_dns_hook_func = std::function< ssize_t(
void *sock, const struct sockaddr *from, ManagedBuffer) >;
// FIXME: llarp::Addr
/// DNS server query request
struct dnsd_question_request
{
/// sock type
void *user;
// raw or llarp subsystem (is this used? does this matter?)
bool llarp;
/// request header
dns_msg_header hdr;
/// question being asked
dns_msg_question question;
// request source socket
struct sockaddr *from; // FIXME: convert to llarp::Addr
sendto_dns_hook_func sendto_hook; // sendto hook tbh
// maybe a reference to dnsd_context incase of multiple
dnsd_context *context; // or you can access it via user (udp)
};
// FIXME: made better as a two way structure, collapse the request and response
// together
struct dnsd_query_hook_response
{
/// turn off communication
bool dontSendResponse;
/// turn off recursion
bool dontLookUp;
/// potential address
llarp::huint32_t returnThis;
};
/// builds and fires a request based based on llarp_udp_io udp event
/// called by the llarp_handle_dns_recvfrom generic (dnsd/dnsc) handler in dns
void
llarp_handle_dnsd_recvfrom(struct llarp_udp_io *udp,
const struct sockaddr *addr, ManagedBuffer buf);
//
// output structures/functions:
//
// we may want to pass dnsd_question_request to these,
// incase we need to send an error back up through the pipeline
// FIXME: just use the from in the request
/// NXDOMAIN not found
void
write404_dnss_response(const dnsd_question_request *request);
/// for hook functions to use
void
writecname_dnss_response(std::string cname,
const dnsd_question_request *request);
// FIXME: llarp::Addr
/// send an A record found response
void
writesend_dnss_response(llarp::huint32_t *hostRes,
const dnsd_question_request *request);
// FIXME: llarp::Addr
/// send an PTR record found response
void
writesend_dnss_revresponse(std::string reverse,
const dnsd_question_request *request);
// FIXME: llarp::Addr
//
// setup/teardown functions/structure:
//
/// intercept query hook functor
using intercept_query_hook = std::function< dnsd_query_hook_response *(
std::string name, const dnsd_question_request *request) >;
// FIXME: llarp::Addr
/// DNS Server context
struct dnsd_context
{
/// DNS daemon socket to listen on
struct llarp_udp_io udp;
/// udp tracker
struct dns_tracker *tracker;
/// upstream DNS client context to use
dnsc_context client;
/// custom data for intercept query hook (used for configuration of hook)
void *user;
/// hook function for intercepting dns requests
intercept_query_hook intercept;
};
/// initialize dns subsystem and bind socket
/// returns true on bind success otherwise returns false
bool
llarp_dnsd_init(struct dnsd_context *const dnsd, llarp::Logic *const logic,
struct llarp_ev_loop *const netloop,
const llarp::Addr &dnsd_sockaddr,
const llarp::Addr &dnsc_sockaddr);
/// shutdowns any events, and deallocates for this context
bool
llarp_dnsd_stop(struct dnsd_context *const dnsd);
#endif