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// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012- OpenVPN Inc.
//
// SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
//
#ifndef OPENVPN_CLIENT_ASYNC_RESOLVE_GENERIC_H
#define OPENVPN_CLIENT_ASYNC_RESOLVE_GENERIC_H
#include <openvpn/common/bigmutex.hpp>
#include <openvpn/common/rc.hpp>
#include <openvpn/common/hostport.hpp>
namespace openvpn {
template <typename RESOLVER_TYPE>
class AsyncResolvable : public virtual RC<thread_unsafe_refcount>
{
private:
typedef RCPtr<AsyncResolvable> Ptr;
openvpn_io::io_context &io_context;
RESOLVER_TYPE resolver;
public:
using resolver_type = RESOLVER_TYPE;
using results_type = typename RESOLVER_TYPE::results_type;
AsyncResolvable(openvpn_io::io_context &io_context_arg)
: io_context(io_context_arg),
resolver(io_context_arg)
{
}
virtual void resolve_callback(const openvpn_io::error_code &error,
results_type results) = 0;
// This implementation assumes that the i/o reactor provides an asynchronous
// DNS resolution routine using its own primitives and that doesn't require
// us to take care of any non-interruptible opration (i.e. getaddrinfo() in
// case of ASIO).
//
// For example, iOS implements aync_resolve using GCD and CFHost. This
// implementation satisfies the constraints mentioned above
virtual void async_resolve_name(const std::string &host, const std::string &port)
{
resolver.async_resolve(host,
port,
[self = Ptr(this)](const openvpn_io::error_code &error, results_type results)
{
OPENVPN_ASYNC_HANDLER;
self->resolve_callback(error, results); });
}
// no-op: needed to provide the same class signature of the ASIO version
void async_resolve_lock()
{
}
void async_resolve_cancel()
{
resolver.cancel();
}
};
} // namespace openvpn
#endif /* OPENVPN_CLIENT_ASYNC_RESOLVE_GENERIC_H */
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