ObjFW  Check-in [4fd5a7086c]

	OFSubarray.m			\
	OFUTF8String.m			\
	${AUTORELEASE_M}		\
	${INSTANCE_M}			\
	${LIBBASES_M}
SRCS_FILES += OFFileURLHandler.m	\
	      OFINIFileSettings.m
SRCS_SOCKETS += OFDNSResolverSettings.m			\
		OFHTTPURLHandler.m			\
		OFKernelEventObserver.m			\
		${OFEPOLLKERNELEVENTOBSERVER_M}		\
		${OFKQUEUEKERNELEVENTOBSERVER_M}	\
		${OFPOLLKERNELEVENTOBSERVER_M}		\
		${OFSELECTKERNELEVENTOBSERVER_M}

OBJS_EXTRA = ${RUNTIME_RUNTIME_A}	\

OF_ASSUME_NONNULL_BEGIN

#define OF_DNS_RESOLVER_BUFFER_LENGTH 512

@class OFArray OF_GENERIC(ObjectType);
@class OFDNSResolver;
@class OFDNSResolverQuery;
@class OFDNSResolverSettings;
@class OFDate;
@class OFDictionary OF_GENERIC(KeyType, ObjectType);
@class OFMutableDictionary OF_GENERIC(KeyType, ObjectType);
@class OFNumber;
@class OFUDPSocket;

/*!

 *	 @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
{

	OFDNSResolverSettings *_settings;








	OFUDPSocket *_IPv4Socket;
#ifdef OF_HAVE_IPV6
	OFUDPSocket *_IPv6Socket;
#endif
	char _buffer[OF_DNS_RESOLVER_BUFFER_LENGTH];
	OFMutableDictionary OF_GENERIC(OFNumber *, OFDNSResolverQuery *)
	    *_queries;

 * 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.
 */

#include "config.h"


#include <string.h>


#import "OFDNSResolver.h"
#import "OFArray.h"
#import "OFDNSRequest.h"
#import "OFDNSResolverSettings.h"
#import "OFDNSResponse.h"
#import "OFData.h"
#import "OFDate.h"
#import "OFDictionary.h"


#import "OFNumber.h"
#import "OFPair.h"
#import "OFString.h"
#import "OFTimer.h"
#import "OFUDPSocket.h"
#import "OFUDPSocket+Private.h"




#import "OFDNSRequestFailedException.h"
#import "OFInitializationFailedException.h"
#import "OFInvalidArgumentException.h"
#import "OFInvalidFormatException.h"
#import "OFInvalidServerReplyException.h"


#import "OFOutOfRangeException.h"
#import "OFTruncatedDataException.h"













#ifndef SOCK_DNS
# define SOCK_DNS 0
#endif

#define BUFFER_LENGTH OF_DNS_RESOLVER_BUFFER_LENGTH

/*
 * RFC 1035 doesn't specify if pointers to pointers are allowed, and if so how
 * many. Since it's unspecified, we have to assume that it might happen, but we
 * also want to limit it to avoid DoS. Limiting it to 16 levels of pointers and
 * immediately rejecting pointers to itself seems like a fair balance.
 */
#define MAX_ALLOWED_POINTERS 16

#define CNAME_RECURSION 3

















/*
 * TODO:
 *
 *  - Fallback to TCP
 */

static const of_run_loop_mode_t resolveRunLoopMode =
    @"of_dns_resolver_resolve_mode";

















@interface OFDNSResolverQuery: OFObject
{
@public
	OFDNSRequest *_request;
	OFString *_domainName;
	OFNumber *_ID;
	OFDNSResolverSettings *_settings;

	bool _done;
	OFData *_socketAddresses;
	id _exception;
}
@end

@interface OFDNSResolver () <OFUDPSocketDelegate>



















- (void)of_asyncPerformRequest: (OFDNSRequest *)request
		      settings: (OFDNSResolverSettings *)settings
	      nameServersIndex: (size_t)nameServersIndex
	    searchDomainsIndex: (size_t)searchDomainsIndex
		   runLoopMode: (of_run_loop_mode_t)runLoopMode
			target: (id)target





		      selector: (SEL)selector
		       context: (id)context;
- (void)of_sendQuery: (OFDNSResolverQuery *)query
	 runLoopMode: (of_run_loop_mode_t)runLoopMode;
- (void)of_queryWithIDTimedOut: (OFDNSResolverQuery *)query;
@end



































static bool
isFQDN(OFString *host, OFDNSResolverSettings *settings)
{
	const char *UTF8String = host.UTF8String;
	size_t length = host.UTF8StringLength;
	unsigned int dots = 0;

	    id, id) = (void (*)(id, SEL, OFDNSResolver *, OFString *,
	    OFDNSResponse *, id, id))[target methodForSelector: selector];

	method(target, selector, resolver, domainName, response, context,
	    exception);
}

































@implementation OFDNSResolverQuery
- (instancetype)initWithRequest: (OFDNSRequest *)request
		     domainName: (OFString *)domainName
			     ID: (OFNumber *)ID
		       settings: (OFDNSResolverSettings *)settings
	       nameServersIndex: (size_t)nameServersIndex
	     searchDomainsIndex: (size_t)searchDomainsIndex

		void *pool = objc_autoreleasePoolPush();
		OFMutableData *queryData;
		uint16_t tmp;

		_request = [request copy];
		_domainName = [domainName copy];
		_ID = [ID retain];
		_settings = [settings copy];
		_nameServersIndex = nameServersIndex;
		_searchDomainsIndex = searchDomainsIndex;
		_target = [target retain];
		_selector = selector;
		_context = [context retain];

		queryData = [OFMutableData dataWithCapacity: 512];

				   secondObject: recordTypeNumber]];

		request = [OFDNSRequest
		    requestWithHost: alias
			recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
			 recordType: recordType];
		[_resolver of_asyncPerformRequest: request
					 settings: nil
				 nameServersIndex: 0
			       searchDomainsIndex: 0
				      runLoopMode: runLoopMode
					   target: self
					 selector: @selector(resolver:
						       didResolveCNAME:response:
						       context:exception:)
					  context: recordTypeNumber];
	}

	_socketAddresses = [socketAddresses retain];
	_exception = [exception retain];
	_done = true;
}
@end

@implementation OFDNSResolver






#ifdef OF_AMIGAOS
+ (void)initialize
{
	if (self != [OFDNSResolver class])
		return;

	if (!of_socket_init())

}

- (instancetype)init
{
	self = [super init];

	@try {
		_settings = [[OFDNSResolverSettings alloc] init];
		_queries = [[OFMutableDictionary alloc] init];


		[_settings reload];
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}





















































































- (void)dealloc
{
	[self close];

	[_settings release];




	[_IPv4Socket cancelAsyncRequests];
	[_IPv4Socket release];
#ifdef OF_HAVE_IPV6
	[_IPv6Socket cancelAsyncRequests];
	[_IPv6Socket release];
#endif
	[_queries release];

	[super dealloc];
}







- (OFDictionary *)staticHosts




{





	return _settings->_staticHosts;
}


- (void)setStaticHosts: (OFDictionary *)staticHosts





{



	OFDictionary *old = _settings->_staticHosts;



	_settings->_staticHosts = [staticHosts copy];

	[old release];

}







- (OFArray *)nameServers





{


	return _settings->_nameServers;

}




- (void)setNameServers: (OFArray *)nameServers

{


	OFArray *old = _settings->_nameServers;


	_settings->_nameServers = [nameServers copy];



	[old release];







}















- (OFString *)localDomain
{



	return _settings->_localDomain;



}




- (OFArray *)searchDomains



{



	return _settings->_searchDomains;
}







- (void)setSearchDomains: (OFArray *)searchDomains








{


	OFArray *old = _settings->_searchDomains;

	_settings->_searchDomains = [searchDomains copy];
	[old release];

}


- (of_time_interval_t)timeout

{




	return _settings->_timeout;





}









- (void)setTimeout: (of_time_interval_t)timeout
{


	_settings->_timeout = timeout;

}



- (unsigned int)maxAttempts


{












	return _settings->_maxAttempts;
}











- (void)setMaxAttempts: (unsigned int)maxAttempts
{



	_settings->_maxAttempts = maxAttempts;
}









- (unsigned int)minNumberOfDotsInAbsoluteName


{



	return _settings->_minNumberOfDotsInAbsoluteName;






}


- (void)setMinNumberOfDotsInAbsoluteName:






    (unsigned int)minNumberOfDotsInAbsoluteName
{
	_settings->_minNumberOfDotsInAbsoluteName =



	    minNumberOfDotsInAbsoluteName;



}











- (bool)usesTCP



{


	return _settings->_usesTCP;
}









- (void)setUsesTCP: (bool)usesTCP


{




	_settings->_usesTCP = usesTCP;



}


- (of_time_interval_t)configReloadInterval

{





	return _settings->_configReloadInterval;


}





- (void)setConfigReloadInterval: (of_time_interval_t)configReloadInterval


{


	_settings->_configReloadInterval = configReloadInterval;






}

- (void)of_asyncPerformRequest: (OFDNSRequest *)request
		      settings: (OFDNSResolverSettings *)settings
	      nameServersIndex: (size_t)nameServersIndex
	    searchDomainsIndex: (size_t)searchDomainsIndex
		   runLoopMode: (of_run_loop_mode_t)runLoopMode
			target: (id)target
		      selector: (SEL)selector
		       context: (id)context
{
	void *pool = objc_autoreleasePoolPush();
	OFNumber *ID;
	OFString *host, *domainName;
	OFDNSResolverQuery *query;

	if (settings == nil) {
		[_settings reload];
		settings = _settings;
	}

	/* Random, unused ID */
	do {
		ID = [OFNumber numberWithUInt16: (uint16_t)of_random()];
	} while ([_queries objectForKey: ID] != nil);

	host = request.host;

			       exception: exception];
}

- (void)asyncPerformRequest: (OFDNSRequest *)request
		   delegate: (id <OFDNSResolverDelegate>)delegate
{
	[self of_asyncPerformRequest: request
			    settings: nil
		    nameServersIndex: 0
		  searchDomainsIndex: 0
			 runLoopMode: of_run_loop_mode_default
			      target: self
			    selector: @selector(of_resolver:
					  didResolveDomainName:response:context:
					  exception:)
			     context: delegate];
}

- (void)asyncPerformRequest: (OFDNSRequest *)request
		runLoopMode: (of_run_loop_mode_t)runLoopMode
		   delegate: (id <OFDNSResolverDelegate>)delegate
{
	[self of_asyncPerformRequest: request
			    settings: nil
		    nameServersIndex: 0
		  searchDomainsIndex: 0
			 runLoopMode: runLoopMode
			      target: self
			    selector: @selector(of_resolver:
					  didResolveDomainName:response:context:
					  exception:)
			     context: delegate];
}




























- (void)of_sendQuery: (OFDNSResolverQuery *)query
	 runLoopMode: (of_run_loop_mode_t)runLoopMode
{
	OFUDPSocket *sock;
	OFString *nameServer;

	[query->_cancelTimer invalidate];

						     forMode: runLoopMode];
		}

		return;
	} @catch (OFInvalidFormatException *e) {
	}

	if ((aliases = [_settings->_staticHosts objectForKey: host]) != nil) {
		OFMutableData *addresses = [OFMutableData
		    dataWithItemSize: sizeof(of_socket_address_t)];
		id exception = nil;

		for (OFString *alias in aliases) {
			of_socket_address_t address;

		    requestWithHost: host
			recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
			 recordType: OF_DNS_RESOURCE_RECORD_TYPE_AAAA];
		OFNumber *recordTypeNumber =
		    [OFNumber numberWithInt: OF_DNS_RESOURCE_RECORD_TYPE_AAAA];

		[self of_asyncPerformRequest: request
				    settings: nil
			    nameServersIndex: 0
			  searchDomainsIndex: 0
				 runLoopMode: runLoopMode
				      target: context
				    selector: @selector(resolver:
						  didResolveDomainName:response:
						  context:exception:)
				     context: recordTypeNumber];
	}
#endif

	if (addressFamily == OF_SOCKET_ADDRESS_FAMILY_IPV4 ||
	    addressFamily == OF_SOCKET_ADDRESS_FAMILY_ANY) {
		OFDNSRequest *request = [OFDNSRequest
		    requestWithHost: host
			recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
			 recordType: OF_DNS_RESOURCE_RECORD_TYPE_A];
		OFNumber *recordTypeNumber =
		    [OFNumber numberWithInt: OF_DNS_RESOURCE_RECORD_TYPE_A];

		[self of_asyncPerformRequest: request
				    settings: nil
			    nameServersIndex: 0
			  searchDomainsIndex: 0
				 runLoopMode: runLoopMode
				      target: context
				    selector: @selector(resolver:
						  didResolveDomainName:response:
						  context:exception:)
				     context: recordTypeNumber];
	}

/*
 * 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"

OF_ASSUME_NONNULL_BEGIN

@class OFArray OF_GENERIC(ObjectType);
@class OFDate;
@class OFDictionary OF_GENERIC(KeyType, ObjectType);

@interface OFDNSResolverSettings: OFObject <OFCopying>
{
@public
	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;
@protected
	OFDate *_lastConfigReload;
}

- (void)reload;
@end

OF_ASSUME_NONNULL_END

/*
 * 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.
 */

#include "config.h"

#include "unistd_wrapper.h"

#import "OFDNSResolverSettings.h"
#import "OFArray.h"
#import "OFCharacterSet.h"
#import "OFDate.h"
#import "OFDictionary.h"
#import "OFFile.h"
#import "OFLocale.h"
#import "OFString.h"
#ifdef OF_WINDOWS
# import "OFWindowsRegistryKey.h"
#endif

#import "OFInvalidFormatException.h"
#import "OFOpenItemFailedException.h"
#import "OFOutOfMemoryException.h"

#ifdef OF_WINDOWS
# define interface struct
# include <iphlpapi.h>
# undef interface
#endif

#ifdef OF_NINTENDO_3DS
# include <3ds.h>
#endif

#import "socket_helpers.h"

#if defined(OF_HAIKU)
# define HOSTS_PATH @"/system/settings/network/hosts"
# define RESOLV_CONF_PATH @"/system/settings/network/resolv.conf"
#elif defined(OF_MORPHOS)
# define HOSTS_PATH @"ENV:sys/net/hosts"
# define RESOLV_CONF_PATH @"ENV:sys/net/resolv.conf"
#elif defined(OF_AMIGAOS4)
# define HOSTS_PATH @"DEVS:Internet/hosts"
#elif defined(OF_AMIGAOS)
# define HOSTS_PATH @"AmiTCP:db/hosts"
# define RESOLV_CONF_PATH @"AmiTCP:db/resolv.conf"
#else
# define HOSTS_PATH @"/etc/hosts"
# define RESOLV_CONF_PATH @"/etc/resolv.conf"
#endif

#ifndef OF_WII
static OFString *
domainFromHostname(void)
{
	char hostname[256];
	OFString *domain;

	if (gethostname(hostname, 256) != 0)
		return nil;

	domain = [OFString stringWithCString: hostname
				    encoding: [OFLocale encoding]];

	@try {
		of_socket_address_parse_ip(domain, 0);

		/*
		 * If we are still here, the host name is a valid IP address.
		 * We can't use that as local domain.
		 */
		return nil;
	} @catch (OFInvalidFormatException *e) {
		/* Not an IP address -> we can use it if it contains a dot. */
		size_t pos = [domain rangeOfString: @"."].location;

		if (pos == OF_NOT_FOUND)
			return nil;

		return [domain substringWithRange:
		    of_range(pos + 1, domain.length - pos - 1)];
	}
}
#endif

@implementation OFDNSResolverSettings
- (void)dealloc
{
	[_staticHosts release];
	[_nameServers release];
	[_localDomain release];
	[_searchDomains release];
	[_lastConfigReload release];

	[super dealloc];
}

- (id)copy
{
	OFDNSResolverSettings *copy = [[OFDNSResolverSettings alloc] init];

	@try {
		copy->_staticHosts = [_staticHosts copy];
		copy->_nameServers = [_nameServers copy];
		copy->_localDomain = [_localDomain copy];
		copy->_searchDomains = [_searchDomains copy];
		copy->_timeout = _timeout;
		copy->_maxAttempts = _maxAttempts;
		copy->_minNumberOfDotsInAbsoluteName =
		    _minNumberOfDotsInAbsoluteName;
		copy->_usesTCP = _usesTCP;
		copy->_configReloadInterval = _configReloadInterval;
		copy->_lastConfigReload = [_lastConfigReload copy];
	} @catch (id e) {
		[copy release];
		@throw e;
	}

	return copy;
}

- (void)setDefaults
{
	[_staticHosts release];
	_staticHosts = nil;

	[_nameServers release];
	_nameServers = nil;

	[_localDomain release];
	_localDomain = nil;

	[_searchDomains release];
	_searchDomains = nil;

	_timeout = 2;
	_maxAttempts = 3;
	_minNumberOfDotsInAbsoluteName = 1;
	_usesTCP = false;
#ifndef OF_NINTENDO_3DS
	_configReloadInterval = 2;
#else
	_configReloadInterval = 0;
#endif
}

#if defined(OF_HAVE_FILES) && !defined(OF_NINTENDO_3DS)
- (void)parseHosts: (OFString *)path
{
	void *pool = objc_autoreleasePoolPush();
	OFCharacterSet *whitespaceCharacterSet =
	    [OFCharacterSet whitespaceCharacterSet];
	OFMutableDictionary *staticHosts;
	OFFile *file;
	OFString *line;
	OFEnumerator *enumerator;
	OFMutableArray *addresses;

	@try {
		file = [OFFile fileWithPath: path
				       mode: @"r"];
	} @catch (OFOpenItemFailedException *e) {
		objc_autoreleasePoolPop(pool);
		return;
	}

	staticHosts = [OFMutableDictionary dictionary];

	while ((line = [file readLine]) != nil) {
		void *pool2 = objc_autoreleasePoolPush();
		OFArray *components, *hosts;
		size_t pos;
		OFString *address;

		pos = [line rangeOfString: @"#"].location;
		if (pos != OF_NOT_FOUND)
			line = [line substringWithRange: of_range(0, pos)];

		components = [line
		    componentsSeparatedByCharactersInSet: whitespaceCharacterSet
						 options: OF_STRING_SKIP_EMPTY];

		if (components.count < 2) {
			objc_autoreleasePoolPop(pool2);
			continue;
		}

		address = components.firstObject;
		hosts = [components objectsInRange:
		    of_range(1, components.count - 1)];

		for (OFString *host in hosts) {
			addresses = [staticHosts objectForKey: host];

			if (addresses == nil) {
				addresses = [OFMutableArray array];
				[staticHosts setObject: addresses
						forKey: host];
			}

			[addresses addObject: address];
		}

		objc_autoreleasePoolPop(pool2);
	}

	enumerator = [staticHosts objectEnumerator];
	while ((addresses = [enumerator nextObject]) != nil)
		[addresses makeImmutable];

	[staticHosts makeImmutable];

	[_staticHosts release];
	_staticHosts = [staticHosts copy];

	objc_autoreleasePoolPop(pool);
}

# if !defined(OF_WINDOWS) && !defined(OF_AMIGAOS4)
- (void)parseResolvConfOption: (OFString *)option
{
	@try {
		if ([option hasPrefix: @"ndots:"]) {
			option = [option substringWithRange:
			    of_range(6, option.length - 6)];

			_minNumberOfDotsInAbsoluteName =
			    (unsigned int)option.decimalValue;
		} else if ([option hasPrefix: @"timeout:"]) {
			option = [option substringWithRange:
			    of_range(8, option.length - 8)];

			_timeout = option.decimalValue;
		} else if ([option hasPrefix: @"attempts:"]) {
			option = [option substringWithRange:
			    of_range(9, option.length - 9)];

			_maxAttempts = (unsigned int)option.decimalValue;
		} else if ([option hasPrefix: @"reload-period:"]) {
			option = [option substringWithRange:
			    of_range(14, option.length - 14)];

			_configReloadInterval = option.decimalValue;
		} else if ([option isEqual: @"tcp"])
			_usesTCP = true;
	} @catch (OFInvalidFormatException *e) {
	}
}

- (void)parseResolvConf: (OFString *)path
{
	void *pool = objc_autoreleasePoolPush();
	OFCharacterSet *whitespaceCharacterSet =
	    [OFCharacterSet whitespaceCharacterSet];
	OFCharacterSet *commentCharacters = [OFCharacterSet
	    characterSetWithCharactersInString: @"#;"];
	OFMutableArray *nameServers = [[_nameServers mutableCopy] autorelease];
	OFFile *file;
	OFString *line;

	@try {
		file = [OFFile fileWithPath: path
				       mode: @"r"];
	} @catch (OFOpenItemFailedException *e) {
		objc_autoreleasePoolPop(pool);
		return;
	}

	if (nameServers == nil)
		nameServers = [OFMutableArray array];

	while ((line = [file readLine]) != nil) {
		void *pool2 = objc_autoreleasePoolPush();
		size_t pos;
		OFArray *components, *arguments;
		OFString *option;

		pos = [line indexOfCharacterFromSet: commentCharacters];
		if (pos != OF_NOT_FOUND)
			line = [line substringWithRange: of_range(0, pos)];

		components = [line
		    componentsSeparatedByCharactersInSet: whitespaceCharacterSet
						 options: OF_STRING_SKIP_EMPTY];

		if (components.count < 2) {
			objc_autoreleasePoolPop(pool2);
			continue;
		}

		option = components.firstObject;
		arguments = [components objectsInRange:
		    of_range(1, components.count - 1)];

		if ([option isEqual: @"nameserver"]) {
			if (arguments.count != 1) {
				objc_autoreleasePoolPop(pool2);
				continue;
			}

			[nameServers addObject: [arguments firstObject]];
		} else if ([option isEqual: @"domain"]) {
			if (arguments.count != 1) {
				objc_autoreleasePoolPop(pool2);
				continue;
			}

			[_localDomain release];
			_localDomain = [arguments.firstObject copy];
		} else if ([option isEqual: @"search"]) {
			[_searchDomains release];
			_searchDomains = [arguments copy];
		} else if ([option isEqual: @"options"])
			for (OFString *argument in arguments)
				[self parseResolvConfOption: argument];

		objc_autoreleasePoolPop(pool2);
	}

	[nameServers makeImmutable];

	[_nameServers release];
	_nameServers = [nameServers copy];

	objc_autoreleasePoolPop(pool);
}
# endif
#endif

#ifdef OF_WINDOWS
- (void)obtainWindowsSystemConfig
{
	of_string_encoding_t encoding = [OFLocale encoding];
	OFMutableArray *nameServers;
	/*
	 * We need more space than FIXED_INFO in case we have more than one
	 * name server, but we also want it to be properly aligned, meaning we
	 * can't just get a buffer of bytes. Thus, we just get space for 8.
	 */
	FIXED_INFO fixedInfo[8];
	ULONG length = sizeof(fixedInfo);
	PIP_ADDR_STRING iter;

	if (GetNetworkParams(fixedInfo, &length) != ERROR_SUCCESS)
		return;

	nameServers = [OFMutableArray array];

	for (iter = &fixedInfo->DnsServerList; iter != NULL; iter = iter->Next)
		[nameServers addObject:
		    [OFString stringWithCString: iter->IpAddress.String
				       encoding: encoding]];

	if (nameServers.count > 0) {
		[nameServers makeImmutable];
		_nameServers = [nameServers copy];
	}

	if (fixedInfo->DomainName[0] != '\0')
		_localDomain = [[OFString alloc]
		    initWithCString: fixedInfo->DomainName
			   encoding: encoding];
}
#endif

#ifdef OF_AMIGAOS4
- (void)obtainAmigaOS4SystemConfig
{
	OFMutableArray *nameServers = [OFMutableArray array];
	of_string_encoding_t encoding = [OFLocale encoding];
	struct List *nameServerList = ObtainDomainNameServerList();
	char buffer[MAXHOSTNAMELEN];

	if (nameServerList == NULL)
		@throw [OFOutOfMemoryException exception];

	@try {
		struct DomainNameServerNode *iter =
		    (struct DomainNameServerNode *)&nameServerList->lh_Head;

		while (iter->dnsn_MinNode.mln_Succ != NULL) {
			if (iter->dnsn_UseCount != 0 &&
			    iter->dnsn_Address != NULL) {
				OFString *address = [OFString
				    stringWithCString: iter->dnsn_Address
					     encoding: encoding];

				[nameServers addObject: address];
			}

			iter = (struct DomainNameServerNode *)
			    iter->dnsn_MinNode.mln_Succ;
		}
	} @finally {
		ReleaseDomainNameServerList(nameServerList);
	}

	if (nameServers.count > 0) {
		[nameServers makeImmutable];
		_nameServers = [nameServers copy];
	}

	if (GetDefaultDomainName(buffer, sizeof(buffer)))
		_localDomain = [[OFString alloc] initWithCString: buffer
							encoding: encoding];
}
#endif

#ifdef OF_NINTENDO_3DS
- (void)obtainNintendo3DSSytemConfig
{
	OFMutableArray *nameServers = [OFMutableArray array];
	union {
		/*
		 * For some unknown reason, this needs a 336 bytes buffer and
		 * always returns 336 bytes.
		 */
		char bytes[336];
		SOCU_DNSTableEntry entries[2];
	} buffer;
	socklen_t optLen = sizeof(buffer);

	if (SOCU_GetNetworkOpt(SOL_CONFIG, NETOPT_DNS_TABLE,
	    &buffer, &optLen) != 0)
		return;

	/*
	 * We're fine if this gets smaller in a future release (unlikely), as
	 * long as two entries still fit.
	 */
	if (optLen < sizeof(buffer.entries))
		return;

	for (uint_fast8_t i = 0; i < 2; i++) {
		uint32_t ip = OF_BSWAP32_IF_LE(buffer.entries[i].ip.s_addr);

		if (ip == 0)
			continue;

		[nameServers addObject: [OFString stringWithFormat:
		    @"%u.%u.%u.%u", (ip >> 24) & 0xFF, (ip >> 16) & 0xFF,
		    (ip >> 8) & 0xFF, ip & 0xFF]];
	}

	if (nameServers.count > 0) {
		[nameServers makeImmutable];
		_nameServers = [nameServers copy];
	}
}
#endif

- (void)reload
{
	void *pool;
#ifdef OF_WINDOWS
	OFString *path;
#endif

	/*
	 * TODO: Rather than reparsing every time, check what actually changed
	 *	 (mtime) and only reset those.
	 */

	if (_lastConfigReload != nil && _configReloadInterval > 0 &&
	    _lastConfigReload.timeIntervalSinceNow < _configReloadInterval)
		return;

	pool = objc_autoreleasePoolPush();

	[self setDefaults];

#if defined(OF_WINDOWS)
# ifdef OF_HAVE_FILES
	path = [[OFWindowsRegistryKey localMachineKey]
	    stringForValue: @"DataBasePath"
		subkeyPath: @"SYSTEM\\CurrentControlSet\\Services\\"
			    @"Tcpip\\Parameters"];
	path = [path stringByAppendingPathComponent: @"hosts"];

	if (path != nil)
		[self parseHosts: path];
# endif

	[self obtainWindowsSystemConfig];
#elif defined(OF_AMIGAOS4)
	[self parseHosts: HOSTS_PATH];
	[self obtainAmigaOS4SystemConfig];
#elif defined(OF_NINTENDO_3DS)
	[self obtainNintendo3DSSytemConfig];
#elif defined(OF_HAVE_FILES)
	[self parseHosts: HOSTS_PATH];
	[self parseResolvConf: RESOLV_CONF_PATH];
#endif

	if (_staticHosts == nil) {
		OFArray *localhost =
#ifdef OF_HAVE_IPV6
		    [OFArray arrayWithObjects: @"::1", @"127.0.0.1", nil];
#else
		    [OFArray arrayWithObject: @"127.0.0.1"];
#endif

		_staticHosts = [[OFDictionary alloc]
		    initWithObject: localhost
			    forKey: @"localhost"];
	}

	if (_nameServers == nil)
#ifdef OF_HAVE_IPV6
		_nameServers = [[OFArray alloc]
		    initWithObjects: @"127.0.0.1", @"::1", nil];
#else
		_nameServers = [[OFArray alloc] initWithObject: @"127.0.0.1"];
#endif

#ifndef OF_WII
	if (_localDomain == nil)
		_localDomain = [domainFromHostname() copy];
#endif

	if (_searchDomains == nil) {
		if (_localDomain != nil)
			_searchDomains = [[OFArray alloc]
			    initWithObject: _localDomain];
		else
			_searchDomains = [[OFArray alloc] init];
	}

	objc_autoreleasePoolPop(pool);
}
@end