lokinet/include/llarp/dnsc.hpp
2018-10-09 05:41:33 -07:00

108 lines
3.1 KiB
C++

#ifndef LIBLLARP_DNSC_HPP
#define LIBLLARP_DNSC_HPP
#include <llarp/ev.h> // for sockaadr
#include <llarp/dns.hpp> // get protocol structs
// 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;
// char *url;
unsigned char request[DNC_BUF_SIZE];
// 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
typedef void (*dnsc_answer_hook_func)(dnsc_answer_request *request);
/// struct for dns client requests
struct dnsc_answer_request
{
/// sock type
void *sock; // pts to udp...
/// customizable (used for hook (outer request))
void *user;
/// storage
dns_msg_question question;
/// hook
dnsc_answer_hook_func resolved;
/// result
bool found;
llarp::Addr 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, const void *buf,
const ssize_t sz);
/// 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);
/// 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)
struct llarp_logic *logic;
};
/// async 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);
/// async 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);
/// 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,
struct 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