/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
* 2018, 2019
* Jonathan Schleifer <js@heap.zone>
*
* All rights reserved.
*
* This file is part of ObjFW. It may be distributed under the terms of the
* Q Public License 1.0, which can be found in the file LICENSE.QPL included in
* the packaging of this file.
*
* Alternatively, it may be distributed under the terms of the GNU General
* Public License, either version 2 or 3, which can be found in the file
* LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
* file.
*/
#import "OFObject.h"
#import "OFDNSResourceRecord.h"
#import "OFRunLoop.h"
#import "OFString.h"
OF_ASSUME_NONNULL_BEGIN
#define OF_DNS_RESOLVER_BUFFER_LENGTH 512
@class OFArray OF_GENERIC(ObjectType);
@class OFDNSResolver;
@class OFDNSResolverQuery;
@class OFDate;
@class OFDictionary OF_GENERIC(KeyType, ObjectType);
@class OFMutableDictionary OF_GENERIC(KeyType, ObjectType);
@class OFNumber;
@class OFUDPSocket;
/*!
* @enum of_dns_resolver_error_t OFDNSResolver.h ObjFW/OFDNSResolver.h
*
* @brief An enum describing why resolving a host failed.
*/
typedef enum of_dns_resolver_error_t {
/*! An unknown error */
OF_DNS_RESOLVER_ERROR_UNKNOWN,
/*! The query timed out */
OF_DNS_RESOLVER_ERROR_TIMEOUT,
/*! The query was canceled */
OF_DNS_RESOLVER_ERROR_CANCELED,
/*!
* No result for the specified host with the specified type and class.
*
* This is only used in situations where this is an error, e.g. when
* trying to connect to a host.
*/
OF_DNS_RESOLVER_ERROR_NO_RESULT,
/*! The server considered the query to be malformed */
OF_DNS_RESOLVER_ERROR_SERVER_INVALID_FORMAT,
/*! The server was unable to process due to an internal error */
OF_DNS_RESOLVER_ERROR_SERVER_FAILURE,
/*! The server returned an error that the domain does not exist */
OF_DNS_RESOLVER_ERROR_SERVER_NAME_ERROR,
/*! The server does not have support for the requested query */
OF_DNS_RESOLVER_ERROR_SERVER_NOT_IMPLEMENTED,
/*! The server refused the query */
OF_DNS_RESOLVER_ERROR_SERVER_REFUSED
} of_dns_resolver_error_t;
typedef OFDictionary OF_GENERIC(OFString *,
OFArray OF_GENERIC(OFDNSResourceRecord *) *) *of_dns_resolver_records_t;
/*!
* @protocol OFDNSResolverDelegate OFDNSResolver.h ObjFW/OFDNSResolver.h
*
* @brief A delegate for OFDNSResolver.
*/
@protocol OFDNSResolverDelegate <OFObject>
@optional
/*!
* @brief This method is called when a DNS resolver resolved a domain name.
*
* @param resolver The acting resolver
* @param domainName The fully qualified domain name used to resolve the host
* @param answerRecords The answer records from the name server, grouped by
* domain name
* @param authorityRecords The authority records from the name server, grouped
* by domain name
* @param additionalRecords Additional records sent by the name server, grouped
* by domain name
* @param exception An exception that happened during resolving, or nil on
* success
*/
- (void)resolver: (OFDNSResolver *)resolver
didResolveDomainName: (OFString *)domainName
answerRecords: (nullable of_dns_resolver_records_t)answerRecords
authorityRecords: (nullable of_dns_resolver_records_t)authorityRecords
additionalRecords: (nullable of_dns_resolver_records_t)additionalRecords
exception: (nullable id)exception;
/*!
* @brief This method is called when a DNS resolver resolved a domain name to
* socket addresses.
*
* @param resolver The acting resolver
* @param domainName The fully qualified domain name used to resolve the host
* @param socketAddresses OFData containing several of_socket_address_t
* @param exception The exception that occurred during resolving, or nil on
* success
*/
- (void)resolver: (OFDNSResolver *)resolver
didResolveDomainName: (OFString *)domainName
socketAddresses: (nullable OFData *)socketAddresses
exception: (nullable id)exception;
@end
/*!
* @class OFDNSResolver OFDNSResolver.h ObjFW/OFDNSResolver.h
*
* @brief A class for resolving DNS names.
*
* @note If you change any of the properties, make sure to set
* @ref configReloadInterval to 0, as otherwise your changes will be
* reverted back to the system configuration on the next periodic config
* reload.
*/
OF_SUBCLASSING_RESTRICTED
@interface OFDNSResolver: OFObject
{
OFDictionary OF_GENERIC(OFString *, OFArray OF_GENERIC(OFString *) *)
*_staticHosts;
OFArray OF_GENERIC(OFString *) *_nameServers;
OFString *_Nullable _localDomain;
OFArray OF_GENERIC(OFString *) *_searchDomains;
of_time_interval_t _timeout;
unsigned int _maxAttempts, _minNumberOfDotsInAbsoluteName;
bool _usesTCP;
of_time_interval_t _configReloadInterval;
OFDate *_lastConfigReload;
OFUDPSocket *_IPv4Socket;
#ifdef OF_HAVE_IPV6
OFUDPSocket *_IPv6Socket;
#endif
char _buffer[OF_DNS_RESOLVER_BUFFER_LENGTH];
OFMutableDictionary OF_GENERIC(OFNumber *, OFDNSResolverQuery *)
*_queries;
}
/*!
* @brief A dictionary of static hosts.
*
* This dictionary is checked before actually looking up a host.
*/
@property (copy, nonatomic) OFDictionary OF_GENERIC(OFString *,
OFArray OF_GENERIC(OFString *) *) *staticHosts;
/*!
* @brief An array of name servers to use.
*
* The name servers are tried in order.
*/
@property (copy, nonatomic) OFArray OF_GENERIC(OFString *) *nameServers;
/*!
* @brief The local domain.
*/
@property OF_NULLABLE_PROPERTY (readonly, nonatomic) OFString *localDomain;
/*!
* @brief The domains to search for queries for short names.
*/
@property (copy, nonatomic) OFArray OF_GENERIC(OFString *) *searchDomains;
/*!
* @brief The timeout, in seconds, after which the next name server should be
* tried.
*/
@property (nonatomic) of_time_interval_t timeout;
/*!
* @brief The number of attempts before giving up to resolve a host.
*
* Trying all name servers once is considered a single attempt.
*/
@property (nonatomic) unsigned int maxAttempts;
/*!
* @brief The minimum number of dots for a name to be considered absolute.
*/
@property (nonatomic) unsigned int minNumberOfDotsInAbsoluteName;
/*!
* @brief Whether the resolver uses TCP to talk to a name server.
*/
@property (nonatomic) bool usesTCP;
/*!
* @brief The interval in seconds in which the config should be reloaded.
*
* Setting this to 0 disables config reloading.
*/
@property (nonatomic) of_time_interval_t configReloadInterval;
/*!
* @brief Creates a new, autoreleased OFDNSResolver.
*/
+ (instancetype)resolver;
/*!
* @brief Initializes an already allocated OFDNSResolver.
*/
- (instancetype)init;
/*!
* @brief Asynchronously resolves the specified host.
*
* @param host The host to resolve
* @param delegate The delegate to use for callbacks
*/
- (void)asyncResolveHost: (OFString *)host
delegate: (id <OFDNSResolverDelegate>)delegate;
/*!
* @brief Asynchronously resolves the specified host.
*
* @param host The host to resolve
* @param recordClass The desired class of the records to query
* @param recordType The desired type of the records to query
* @param delegate The delegate to use for callbacks
*/
- (void)asyncResolveHost: (OFString *)host
recordClass: (of_dns_resource_record_class_t)recordClass
recordType: (of_dns_resource_record_type_t)recordType
delegate: (id <OFDNSResolverDelegate>)delegate;
/*!
* @brief Asynchronously resolves the specified host.
*
* @param host The host to resolve
* @param recordClass The desired class of the records to query
* @param recordType The desired type of the records to query
* @param runLoopMode The run loop mode in which to resolve
* @param delegate The delegate to use for callbacks
*/
- (void)asyncResolveHost: (OFString *)host
recordClass: (of_dns_resource_record_class_t)recordClass
recordType: (of_dns_resource_record_type_t)recordType
runLoopMode: (of_run_loop_mode_t)runLoopMode
delegate: (id <OFDNSResolverDelegate>)delegate;
/*!
* @brief Asynchronously resolves the specified host to socket addresses.
*
* @param host The host to resolve
* @param delegate The delegate to use for callbacks
*/
- (void)asyncResolveSocketAddressesForHost: (OFString *)host
delegate: (id <OFDNSResolverDelegate>)
delegate;
/*!
* @brief Asynchronously resolves the specified host to socket addresses.
*
* @param host The host to resolve
* @param addressFamily The desired socket address family
* @param delegate The delegate to use for callbacks
*/
- (void)asyncResolveSocketAddressesForHost: (OFString *)host
addressFamily: (of_socket_address_family_t)
addressFamily
delegate: (id <OFDNSResolverDelegate>)
delegate;
/*!
* @brief Asynchronously resolves the specified host to socket addresses.
*
* @param host The host to resolve
* @param addressFamily The desired socket address family
* @param runLoopMode The run loop mode in which to resolve
* @param delegate The delegate to use for callbacks
*/
- (void)asyncResolveSocketAddressesForHost: (OFString *)host
addressFamily: (of_socket_address_family_t)
addressFamily
runLoopMode: (of_run_loop_mode_t)runLoopMode
delegate: (id <OFDNSResolverDelegate>)
delegate;
/*!
* @brief Synchronously resolves the specified host to socket addresses.
*
* @param host The host to resolve
* @param addressFamily The desired socket address family
* @return OFData containing several of_socket_address_t
*/
- (OFData *)resolveSocketAddressesForHost: (OFString *)host
addressFamily: (of_socket_address_family_t)
addressFamily;
/*!
* @brief Closes all sockets and cancels all ongoing requests.
*/
- (void)close;
@end
OF_ASSUME_NONNULL_END