FXSend/MobsetHttp/Poco/Net/DNS.h
2025-02-28 17:05:50 +08:00

200 lines
6.4 KiB
C++

//
// DNS.h
//
// Library: Net
// Package: NetCore
// Module: DNS
//
// Definition of the DNS class.
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Net_DNS_INCLUDED
#define Net_DNS_INCLUDED
#include "Poco/Net/Net.h"
#include "Poco/Net/SocketDefs.h"
#include "Poco/Net/IPAddress.h"
#include "Poco/Net/HostEntry.h"
namespace Poco {
namespace Net {
class Net_API DNS
/// This class provides an interface to the
/// domain name service.
///
/// Starting with POCO C++ Libraries release 1.9.0,
/// this class also supports Internationalized Domain Names (IDNs).
///
/// Regarding IDNs, the following rules apply:
///
/// * An IDN passed to hostByName() must be encoded manually, by calling
/// encodeIDN() (after testing with isIDN() first).
/// * An UTF-8 IDN passed to resolve() or resolveOne() is automatically encoded.
/// * IDNs returned in HostEntry objects are never decoded. They can be
/// decoded by calling decodeIDN() (after testing for an encoded IDN by
/// calling isEncodedIDN()).
{
public:
enum HintFlag
{
DNS_HINT_NONE = 0,
#ifdef POCO_HAVE_ADDRINFO
DNS_HINT_AI_PASSIVE = AI_PASSIVE, /// Socket address will be used in bind() call
DNS_HINT_AI_CANONNAME = AI_CANONNAME, /// Return canonical name in first ai_canonname
DNS_HINT_AI_NUMERICHOST = AI_NUMERICHOST, /// Nodename must be a numeric address string
DNS_HINT_AI_NUMERICSERV = AI_NUMERICSERV, /// Servicename must be a numeric port number
DNS_HINT_AI_ALL = AI_ALL, /// Query both IP6 and IP4 with AI_V4MAPPED
DNS_HINT_AI_ADDRCONFIG = AI_ADDRCONFIG, /// Resolution only if global address configured
DNS_HINT_AI_V4MAPPED = AI_V4MAPPED /// On v6 failure, query v4 and convert to V4MAPPED format
#endif
};
static HostEntry hostByName(const std::string& hostname, unsigned hintFlags =
#ifdef POCO_HAVE_ADDRINFO
DNS_HINT_AI_CANONNAME | DNS_HINT_AI_ADDRCONFIG
#else
DNS_HINT_NONE
#endif
);
/// Returns a HostEntry object containing the DNS information
/// for the host with the given name. HintFlag argument is only
/// used on platforms that have getaddrinfo().
///
/// Note that Internationalized Domain Names must be encoded
/// using Punycode (see encodeIDN()) before calling this method.
///
/// Throws a HostNotFoundException if a host with the given
/// name cannot be found.
///
/// Throws a NoAddressFoundException if no address can be
/// found for the hostname.
///
/// Throws a DNSException in case of a general DNS error.
///
/// Throws an IOException in case of any other error.
static HostEntry hostByAddress(const IPAddress& address, unsigned hintFlags =
#ifdef POCO_HAVE_ADDRINFO
DNS_HINT_AI_CANONNAME | DNS_HINT_AI_ADDRCONFIG
#else
DNS_HINT_NONE
#endif
);
/// Returns a HostEntry object containing the DNS information
/// for the host with the given IP address. HintFlag argument is only
/// used on platforms that have getaddrinfo().
///
/// Throws a HostNotFoundException if a host with the given
/// name cannot be found.
///
/// Throws a DNSException in case of a general DNS error.
///
/// Throws an IOException in case of any other error.
static HostEntry resolve(const std::string& address);
/// Returns a HostEntry object containing the DNS information
/// for the host with the given IP address or host name.
///
/// If address contains a UTF-8 encoded IDN (internationalized
/// domain name), the domain name will be encoded first using
/// Punycode.
///
/// Throws a HostNotFoundException if a host with the given
/// name cannot be found.
///
/// Throws a NoAddressFoundException if no address can be
/// found for the hostname.
///
/// Throws a DNSException in case of a general DNS error.
///
/// Throws an IOException in case of any other error.
static IPAddress resolveOne(const std::string& address);
/// Convenience method that calls resolve(address) and returns
/// the first address from the HostInfo.
static HostEntry thisHost();
/// Returns a HostEntry object containing the DNS information
/// for this host.
///
/// Throws a HostNotFoundException if DNS information
/// for this host cannot be found.
///
/// Throws a NoAddressFoundException if no address can be
/// found for this host.
///
/// Throws a DNSException in case of a general DNS error.
///
/// Throws an IOException in case of any other error.
static void reload();
/// Reloads the resolver configuration.
///
/// This method will call res_init() if the Net library
/// has been compiled with -DPOCO_HAVE_LIBRESOLV. Otherwise
/// it will do nothing.
static std::string hostName();
/// Returns the host name of this host.
static bool isIDN(const std::string& hostname);
/// Returns true if the given hostname is an internationalized
/// domain name (IDN) containing non-ASCII characters, otherwise false.
///
/// The IDN must be UTF-8 encoded.
static bool isEncodedIDN(const std::string& hostname);
/// Returns true if the given hostname is an Punycode-encoded
/// internationalized domain name (IDN), otherwise false.
///
/// An encoded IDN starts with the character sequence "xn--".
static std::string encodeIDN(const std::string& idn);
/// Encodes the given IDN (internationalized domain name), which must
/// be in UTF-8 encoding.
///
/// The resulting string will be encoded according to Punycode.
static std::string decodeIDN(const std::string& encodedIDN);
/// Decodes the given Punycode-encoded IDN (internationalized domain name).
///
/// The resulting string will be UTF-8 encoded.
protected:
static int lastError();
/// Returns the code of the last error.
static void error(int code, const std::string& arg);
/// Throws an exception according to the error code.
static void aierror(int code, const std::string& arg);
/// Throws an exception according to the getaddrinfo() error code.
static std::string encodeIDNLabel(const std::string& idn);
/// Encodes the given IDN (internationalized domain name) label, which must
/// be in UTF-8 encoding.
///
/// The resulting string will be encoded according to Punycode.
static std::string decodeIDNLabel(const std::string& encodedIDN);
/// Decodes the given Punycode-encoded IDN (internationalized domain name) label.
///
/// The resulting string will be UTF-8 encoded.
};
} } // namespace Poco::Net
#endif // Net_DNS_INCLUDED