chromium/net/dns/dns_config_service_posix.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_DNS_DNS_CONFIG_SERVICE_POSIX_H_
#define NET_DNS_DNS_CONFIG_SERVICE_POSIX_H_

#include <netinet/in.h>
#include <resolv.h>
#include <sys/types.h>

#include <memory>
#include <optional>

#include "base/compiler_specific.h"
#include "base/gtest_prod_util.h"
#include "net/base/net_export.h"
#include "net/dns/dns_config_service.h"

namespace net {
struct DnsConfig;

// Use DnsConfigService::CreateSystemService to use it outside of tests.
namespace internal {

// Service for reading and watching POSIX system (except Android and Linux) DNS
// settings.
// This object is not thread-safe and methods may perform blocking I/O so
// methods must be called on a sequence that allows blocking (i.e.
// base::MayBlock). It may be constructed on a different sequence than which
// it's later called on. WatchConfig() must be called prior to ReadConfig().
class NET_EXPORT_PRIVATE DnsConfigServicePosix : public DnsConfigService { … };

// Returns nullopt iff a valid config could not be determined.
std::optional<DnsConfig> NET_EXPORT_PRIVATE
ConvertResStateToDnsConfig(const struct __res_state& res);

}  // namespace internal

}  // namespace net

#endif  // NET_DNS_DNS_CONFIG_SERVICE_POSIX_H_