lokinet/llarp/dns/server.hpp
2021-02-17 13:32:55 -05:00

128 lines
3.0 KiB
C++

#ifndef LLARP_DNS_SERVER_HPP
#define LLARP_DNS_SERVER_HPP
#include <dns/message.hpp>
#include <ev/ev.h>
#include <net/net.hpp>
#include <util/thread/logic.hpp>
#include <dns/unbound_resolver.hpp>
#include <unordered_map>
namespace llarp
{
namespace dns
{
/// handler of dns query hooking
struct IQueryHandler
{
virtual ~IQueryHandler() = default;
/// return true if we should hook this message
virtual bool
ShouldHookDNSMessage(const Message& msg) const = 0;
/// handle a hooked message
virtual bool
HandleHookedDNSMessage(Message query, std::function<void(Message)> sendReply) = 0;
};
struct Proxy : public std::enable_shared_from_this<Proxy>
{
using Logic_ptr = std::shared_ptr<Logic>;
Proxy(
llarp_ev_loop_ptr serverLoop,
Logic_ptr serverLogic,
llarp_ev_loop_ptr clientLoop,
Logic_ptr clientLogic,
IQueryHandler* handler);
bool
Start(const IpAddress& addr, const std::vector<IpAddress>& resolvers);
void
Stop();
void
Restart();
using Buffer_t = std::vector<uint8_t>;
private:
/// low level packet handler
static void
HandleUDPRecv_client(llarp_udp_io*, const SockAddr&, ManagedBuffer);
static void
HandleUDPRecv_server(llarp_udp_io*, const SockAddr&, ManagedBuffer);
/// low level ticker
static void
HandleTick(llarp_udp_io*);
void
HandlePktClient(const SockAddr& from, Buffer_t buf);
void
HandlePktServer(const SockAddr& from, Buffer_t buf);
void
SendClientMessageTo(const SockAddr& to, Message msg);
void
SendServerMessageBufferTo(const SockAddr& to, const llarp_buffer_t& buf);
void
SendServerMessageTo(const SockAddr& to, Message msg);
void
HandleUpstreamResponse(SockAddr to, std::vector<byte_t> buf);
void
HandleUpstreamFailure(const SockAddr& to, Message msg);
IpAddress
PickRandomResolver() const;
bool
SetupUnboundResolver(const std::vector<IpAddress>& resolvers);
private:
llarp_udp_io m_Server;
llarp_udp_io m_Client;
llarp_ev_loop_ptr m_ServerLoop;
llarp_ev_loop_ptr m_ClientLoop;
Logic_ptr m_ServerLogic;
Logic_ptr m_ClientLogic;
IQueryHandler* m_QueryHandler;
std::vector<IpAddress> m_Resolvers;
std::shared_ptr<UnboundResolver> m_UnboundResolver;
struct TX
{
MsgID_t txid;
IpAddress from;
bool
operator==(const TX& other) const
{
return txid == other.txid && from == other.from;
}
struct Hash
{
size_t
operator()(const TX& t) const noexcept
{
return t.txid ^ IpAddress::Hash()(t.from);
}
};
};
// maps tx to who to send reply to
std::unordered_map<TX, IpAddress, TX::Hash> m_Forwarded;
};
} // namespace dns
} // namespace llarp
#endif