lokinet/llarp/dnsc.hpp
2019-08-29 07:45:58 -04:00

120 lines
3.4 KiB
C++

#ifndef LLARP_DNSC_HPP
#define LLARP_DNSC_HPP
#include <dns.hpp> // get protocol structs
#include <ev/ev.h> // for sockaadr
// internal, non-public functions
// well dnsc init/stop are public...
struct dnsc_answer_request;
#define DNC_BUF_SIZE 512
/// a question to be asked remotely (the actual bytes to send on the wire)
// header, question
struct dns_query
{
uint16_t length;
unsigned char request[DNC_BUF_SIZE];
// char *url;
// uint16_t reqType;
};
struct dns_query *
build_dns_packet(char *url, uint16_t id, uint16_t reqType);
/// hook function to handle an dns client request
// should we pass by llarp::Addr
// not as long as we're supporting raw
using dnsc_answer_hook_func = void (*)(dnsc_answer_request *);
/// struct for dns client requests
struct dnsc_answer_request
{
/// sock type
void *sock; // points to udp that sent the request to DNSc...
/// customizable (used for hook (outer request))
void *user;
/// request storage
dns_msg_question question;
/// response storage
dns_packet packet;
/// hook
dnsc_answer_hook_func resolved;
/// result
bool found;
// llarp::huint32_t result;
// std::string revDNS;
// a reference to dnsc_context incase of multiple contexts
struct dnsc_context *context;
};
/// event handler for processing DNS responses
void
llarp_handle_dnsc_recvfrom(struct llarp_udp_io *const udp,
const struct sockaddr *addr, ManagedBuffer buf);
/// generic handler for processing DNS responses
/// this doesn't look like it exists
/// that's because raw_resolve_host calls generic_handle_dnsc_recvfrom directly
/// because we don't need a callback like recvfrom
/// because we're not evented
/// however daemon/dns expects this
/*
void
raw_handle_recvfrom(int *sockfd, const struct sockaddr *addr, const void *buf,
const ssize_t sz);
*/
// removed saddr, if needed get through request
void
generic_handle_dnsc_recvfrom(dnsc_answer_request *request,
const llarp_buffer_t &buffer, dns_msg_header *hdr);
/// DNS client context (one needed per upstream DNS server)
struct dnsc_context
{
/// Target: DNS servers to use
std::vector< llarp::Addr > resolvers;
/// udp tracker
struct dns_tracker *tracker;
/// sock type
void *sock;
// where to create the new sockets
struct llarp_udp_io *udp;
/// We will likely need something for timing events (timeouts)
llarp::Logic *logic;
};
/// async (blocking w/callback) resolve a hostname using generic socks
void
raw_resolve_host(struct dnsc_context *const dnsc, const char *url,
dnsc_answer_hook_func resolved, void *const user,
uint16_t type);
/// async (non blocking w/callback) resolve a hostname using llarp platform
/// framework
bool
llarp_resolve_host(struct dnsc_context *const dns, const char *url,
dnsc_answer_hook_func resolved, void *const user,
uint16_t type);
/// cleans up request structure allocations
void
llarp_host_resolved(dnsc_answer_request *const request);
/// initialize dns subsystem and bind socket
/// returns true on bind success otherwise returns false
bool
llarp_dnsc_init(struct dnsc_context *const dnsc, llarp::Logic *const logic,
struct llarp_ev_loop *const netloop,
const llarp::Addr &dnsc_sockaddr);
/// shutdowns any events, and deallocates for this context
bool
llarp_dnsc_stop(struct dnsc_context *const dnsc);
#endif