/*
 * 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 <string.h>

#import "OFDNSResolver.h"
#import "OFArray.h"
#import "OFDNSQuery.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 "OFDNSQueryFailedException.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
	OFDNSQuery *_query;
	OFString *_domainName;
	OFNumber *_ID;
	OFDNSResolverSettings *_settings;
	size_t _nameServersIndex, _searchDomainsIndex;
	unsigned int _attempt;
	id _target;
	SEL _selector;
	id _context;
	OFData *_queryData;
	of_socket_address_t _usedNameServer;
	OFTimer *_cancelTimer;
}

- (instancetype)initWithQuery: (OFDNSQuery *)query
		   domainName: (OFString *)domainName
			   ID: (OFNumber *)ID
		     settings: (OFDNSResolverSettings *)settings
	     nameServersIndex: (size_t)nameServersIndex
	   searchDomainsIndex: (size_t)searchDomainsIndex
		       target: (id)target
		     selector: (SEL)selector
		      context: (id)context;
@end

@interface OFDNSResolverAsyncResolveSocketAddressesContext: OFObject
{
	OFString *_host;
	id _delegate;
	OFMutableArray OF_GENERIC(OF_KINDOF(OFDNSResourceRecord *)) *_records;
	OFDNSResolver *_resolver;
	OFString *_domainName;
@public
	unsigned int _expectedResponses;
}

- (instancetype)initWithHost: (OFString *)host
		    delegate: (id)delegate;
- (bool)parseRecords: (OFArray *)records
	    response: (OFDNSResponse *)response
	  recordType: (of_dns_resource_record_type_t)recordType
	   recursion: (unsigned int)recursion
	      result: (OFMutableArray *)result;
- (void)resolveCNAME: (OFCNAMEDNSResourceRecord *)CNAME
	    response: (OFDNSResponse *)response
	  recordType: (of_dns_resource_record_type_t)recordType
	   recursion: (unsigned int)recursion
	      result: (OFMutableArray *)result;
-  (void)resolver: (OFDNSResolver *)resolver
  didResolveCNAME: (OFString *)CNAME
	 response: (OFDNSResponse *)response
	  context: (OFNumber *)context
	exception: (id)exception;
- (void)done;
-	(void)resolver: (OFDNSResolver *)resolver
  didResolveDomainName: (OFString *)domainName
	      response: (OFDNSResponse *)response
	       context: (OFNumber *)context
	     exception: (id)exception;
@end

@interface OFDNSResolverResolveSocketAddressesDelegate: OFObject
    <OFDNSResolverDelegate>
{
@public
	bool _done;
	OFData *_socketAddresses;
	id _exception;
}
@end

@interface OFDNSResolver () <OFUDPSocketDelegate>
- (void)of_asyncPerformQuery: (OFDNSQuery *)query
		    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;

	if ([host hasSuffix: @"."])
		return true;

	for (size_t i = 0; i < length; i++)
		if (UTF8String[i] == '.')
			dots++;

	return (dots >= settings->_minNumberOfDotsInAbsoluteName);
}

static OFString *
parseString(const unsigned char *buffer, size_t length, size_t *i)
{
	uint8_t stringLength;
	OFString *string;

	if (*i >= length)
		@throw [OFTruncatedDataException exception];

	stringLength = buffer[(*i)++];

	if (*i + stringLength > length)
		@throw [OFTruncatedDataException exception];

	string = [OFString stringWithUTF8String: (char *)&buffer[*i]
					 length: stringLength];
	*i += stringLength;

	return string;
}

static OFString *
parseName(const unsigned char *buffer, size_t length, size_t *i,
    uint_fast8_t pointerLevel)
{
	OFMutableArray *components = [OFMutableArray array];
	uint8_t componentLength;

	do {
		OFString *component;

		if (*i >= length)
			@throw [OFTruncatedDataException exception];

		componentLength = buffer[(*i)++];

		if (componentLength & 0xC0) {
			size_t j;
			OFString *suffix;

			if (pointerLevel == 0)
				@throw [OFInvalidServerReplyException
				    exception];

			if (*i >= length)
				@throw [OFTruncatedDataException exception];

			j = ((componentLength & 0x3F) << 8) | buffer[(*i)++];

			if (j == *i - 2)
				/* Pointing to itself?! */
				@throw [OFInvalidServerReplyException
				    exception];

			suffix = parseName(buffer, length, &j,
			    pointerLevel - 1);

			if (components.count == 0)
				return suffix;
			else {
				[components addObject: suffix];
				return [components
				    componentsJoinedByString: @"."];
			}
		}

		if (*i + componentLength > length)
			@throw [OFTruncatedDataException exception];

		component = [OFString stringWithUTF8String: (char *)&buffer[*i]
						    length: componentLength];
		*i += componentLength;

		[components addObject: component];
	} while (componentLength > 0);

	return [components componentsJoinedByString: @"."];
}

static OF_KINDOF(OFDNSResourceRecord *)
parseResourceRecord(OFString *name, of_dns_resource_record_class_t recordClass,
    of_dns_resource_record_type_t recordType, uint32_t TTL,
    const unsigned char *buffer, size_t length, size_t i, uint16_t dataLength)
{
	if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_A &&
	    recordClass == OF_DNS_RESOURCE_RECORD_CLASS_IN) {
		of_socket_address_t address;

		if (dataLength != 4)
			@throw [OFInvalidServerReplyException exception];

		memset(&address, 0, sizeof(address));
		address.family = OF_SOCKET_ADDRESS_FAMILY_IPV4;
		address.length = sizeof(address.sockaddr.in);

		address.sockaddr.in.sin_family = AF_INET;
		memcpy(&address.sockaddr.in.sin_addr.s_addr, buffer + i, 4);

		return [[[OFADNSResourceRecord alloc]
		    initWithName: name
			 address: &address
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_NS) {
		size_t j = i;
		OFString *authoritativeHost = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFNSDNSResourceRecord alloc]
			 initWithName: name
			  recordClass: recordClass
		    authoritativeHost: authoritativeHost
				  TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_CNAME) {
		size_t j = i;
		OFString *alias = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFCNAMEDNSResourceRecord alloc]
		    initWithName: name
		     recordClass: recordClass
			   alias: alias
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_SOA) {
		size_t j = i;
		OFString *primaryNameServer = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);
		OFString *responsiblePerson;
		uint32_t serialNumber, refreshInterval, retryInterval;
		uint32_t expirationInterval, minTTL;

		if (j > i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		responsiblePerson = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);

		if (dataLength - (j - i) != 20)
			@throw [OFInvalidServerReplyException exception];

		serialNumber = (buffer[j] << 24) | (buffer[j + 1] << 16) |
		    (buffer[j + 2] << 8) | buffer[j + 3];
		refreshInterval = (buffer[j + 4] << 24) |
		    (buffer[j + 5] << 16) | (buffer[j + 6] << 8) |
		    buffer[j + 7];
		retryInterval = (buffer[j + 8] << 24) | (buffer[j + 9] << 16) |
		    (buffer[j + 10] << 8) | buffer[j + 11];
		expirationInterval = (buffer[j + 12] << 24) |
		    (buffer[j + 13] << 16) | (buffer[j + 14] << 8) |
		    buffer[j + 15];
		minTTL = (buffer[j + 16] << 24) | (buffer[j + 17] << 16) |
		    (buffer[j + 18] << 8) | buffer[j + 19];

		return [[[OFSOADNSResourceRecord alloc]
			  initWithName: name
			   recordClass: recordClass
		     primaryNameServer: primaryNameServer
		     responsiblePerson: responsiblePerson
			  serialNumber: serialNumber
		       refreshInterval: refreshInterval
			 retryInterval: retryInterval
		    expirationInterval: expirationInterval
				minTTL: minTTL
				   TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_PTR) {
		size_t j = i;
		OFString *domainName = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFPTRDNSResourceRecord alloc]
		    initWithName: name
		     recordClass: recordClass
		      domainName: domainName
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_HINFO) {
		size_t j = i;
		OFString *CPU = parseString(buffer, length, &j);
		OFString *OS;

		if (j > i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		OS = parseString(buffer, length, &j);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFHINFODNSResourceRecord alloc]
		    initWithName: name
		     recordClass: recordClass
			     CPU: CPU
			      OS: OS
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_MX) {
		uint16_t preference;
		size_t j;
		OFString *mailExchange;

		if (dataLength < 2)
			@throw [OFInvalidServerReplyException exception];

		preference = (buffer[i] << 8) | buffer[i + 1];

		j = i + 2;
		mailExchange = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFMXDNSResourceRecord alloc]
			    initWithName: name
			     recordClass: recordClass
			      preference: preference
			    mailExchange: mailExchange
				     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_TXT) {
		OFData *textData = [OFData dataWithItems: &buffer[i]
						   count: dataLength];

		return [[[OFTXTDNSResourceRecord alloc]
		    initWithName: name
		     recordClass: recordClass
			textData: textData
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_RP) {
		size_t j = i;
		OFString *mailbox = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);
		OFString *TXTDomainName;

		if (j > i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		TXTDomainName = parseName(buffer, length, &j,
		    MAX_ALLOWED_POINTERS);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFRPDNSResourceRecord alloc]
		    initWithName: name
		     recordClass: recordClass
			 mailbox: mailbox
		   TXTDomainName: TXTDomainName
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_AAAA &&
	    recordClass == OF_DNS_RESOURCE_RECORD_CLASS_IN) {
		of_socket_address_t address;

		if (dataLength != 16)
			@throw [OFInvalidServerReplyException exception];

		memset(&address, 0, sizeof(address));
		address.family = OF_SOCKET_ADDRESS_FAMILY_IPV6;
		address.length = sizeof(address.sockaddr.in6);

#ifdef AF_INET6
		address.sockaddr.in6.sin6_family = AF_INET6;
#else
		address.sockaddr.in6.sin6_family = AF_UNSPEC;
#endif
		memcpy(address.sockaddr.in6.sin6_addr.s6_addr, buffer + i, 16);

		return [[[OFAAAADNSResourceRecord alloc]
		    initWithName: name
			 address: &address
			     TTL: TTL] autorelease];
	} else if (recordType == OF_DNS_RESOURCE_RECORD_TYPE_SRV &&
	    recordClass == OF_DNS_RESOURCE_RECORD_CLASS_IN) {
		uint16_t priority, weight, port;
		size_t j;
		OFString *target;

		if (dataLength < 6)
			@throw [OFInvalidServerReplyException exception];

		priority = (buffer[i] << 8) | buffer[i + 1];
		weight = (buffer[i + 2] << 8) | buffer[i + 3];
		port = (buffer[i + 4] << 8) | buffer[i + 5];

		j = i + 6;
		target = parseName(buffer, length, &j, MAX_ALLOWED_POINTERS);

		if (j != i + dataLength)
			@throw [OFInvalidServerReplyException exception];

		return [[[OFSRVDNSResourceRecord alloc]
			    initWithName: name
				priority: priority
				  weight: weight
				  target: target
				    port: port
				     TTL: TTL] autorelease];
	} else
		return [[[OFDNSResourceRecord alloc]
		    initWithName: name
		     recordClass: recordClass
		      recordType: recordType
			     TTL: TTL] autorelease];
}

static OFDictionary *
parseSection(const unsigned char *buffer, size_t length, size_t *i,
    uint_fast16_t count)
{
	OFMutableDictionary *ret = [OFMutableDictionary dictionary];
	OFEnumerator OF_GENERIC(OFMutableArray *) *objectEnumerator;
	OFMutableArray *array;

	for (uint_fast16_t j = 0; j < count; j++) {
		OFString *name = parseName(buffer, length, i,
		    MAX_ALLOWED_POINTERS);
		of_dns_resource_record_class_t recordClass;
		of_dns_resource_record_type_t recordType;
		uint32_t TTL;
		uint16_t dataLength;
		OFDNSResourceRecord *record;

		if (*i + 10 > length)
			@throw [OFTruncatedDataException exception];

		recordType = (buffer[*i] << 16) | buffer[*i + 1];
		recordClass = (buffer[*i + 2] << 16) | buffer[*i + 3];
		TTL = (buffer[*i + 4] << 24) | (buffer[*i + 5] << 16) |
		    (buffer[*i + 6] << 8) | buffer[*i + 7];
		dataLength = (buffer[*i + 8] << 16) | buffer[*i + 9];

		*i += 10;

		if (*i + dataLength > length)
			@throw [OFTruncatedDataException exception];

		record = parseResourceRecord(name, recordClass, recordType, TTL,
		    buffer, length, *i, dataLength);
		*i += dataLength;

		array = [ret objectForKey: name];

		if (array == nil) {
			array = [OFMutableArray array];
			[ret setObject: array
				forKey: name];
		}

		[array addObject: record];
	}

	objectEnumerator = [ret objectEnumerator];
	while ((array = [objectEnumerator nextObject]) != nil)
		[array makeImmutable];

	[ret makeImmutable];

	return ret;
}

static void
callback(id target, SEL selector, OFDNSResolver *resolver, OFString *domainName,
    OFDNSResponse *response, id context, id exception)
{
	void (*method)(id, SEL, OFDNSResolver *, OFString *, OFDNSResponse *,
	    id, id) = (void (*)(id, SEL, OFDNSResolver *, OFString *,
	    OFDNSResponse *, id, id))[target methodForSelector: selector];

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

@implementation OFDNSResolverQuery
- (instancetype)initWithQuery: (OFDNSQuery *)query
		   domainName: (OFString *)domainName
			   ID: (OFNumber *)ID
		     settings: (OFDNSResolverSettings *)settings
	     nameServersIndex: (size_t)nameServersIndex
	   searchDomainsIndex: (size_t)searchDomainsIndex
		       target: (id)target
		     selector: (SEL)selector
		      context: (id)context
{
	self = [super init];

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

		_query = [query 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];

		/* Header */

		tmp = OF_BSWAP16_IF_LE(_ID.uInt16Value);
		[queryData addItems: &tmp
			      count: 2];

		/* RD */
		tmp = OF_BSWAP16_IF_LE(1u << 8);
		[queryData addItems: &tmp
			      count: 2];

		/* QDCOUNT */
		tmp = OF_BSWAP16_IF_LE(1);
		[queryData addItems: &tmp
			      count: 2];

		/* ANCOUNT, NSCOUNT and ARCOUNT */
		[queryData increaseCountBy: 6];

		/* Question */

		/* QNAME */
		for (OFString *component in
		    [_domainName componentsSeparatedByString: @"."]) {
			size_t length = component.UTF8StringLength;
			uint8_t length8;

			if (length > 63 || queryData.count + length > 512)
				@throw [OFOutOfRangeException exception];

			length8 = (uint8_t)length;
			[queryData addItem: &length8];
			[queryData addItems: component.UTF8String
				      count: length];
		}

		/* QTYPE */
		tmp = OF_BSWAP16_IF_LE(_query.recordType);
		[queryData addItems: &tmp
			      count: 2];

		/* QCLASS */
		tmp = OF_BSWAP16_IF_LE(_query.recordClass);
		[queryData addItems: &tmp
			      count: 2];

		[queryData makeImmutable];

		_queryData = [queryData copy];

		objc_autoreleasePoolPop(pool);
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	[_query release];
	[_domainName release];
	[_ID release];
	[_settings release];
	[_target release];
	[_context release];
	[_queryData release];
	[_cancelTimer release];

	[super dealloc];
}
@end

@implementation OFDNSResolverAsyncResolveSocketAddressesContext
- (instancetype)initWithHost: (OFString *)host
		    delegate: (id)delegate
{
	self = [super init];

	@try {
		_host = [host copy];
		_delegate = [delegate retain];

		_records = [[OFMutableArray alloc] init];
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	[_host release];
	[_delegate release];
	[_records release];
	[_resolver release];
	[_domainName release];

	[super dealloc];
}

- (bool)parseRecords: (OFArray *)records
	    response: (OFDNSResponse *)response
	  recordType: (of_dns_resource_record_type_t)recordType
	   recursion: (unsigned int)recursion
	      result: (OFMutableArray *)result
{
	bool found = false;

	for (OF_KINDOF(OFDNSResourceRecord *) record in records) {
		if ([record recordClass] != OF_DNS_RESOURCE_RECORD_CLASS_IN)
			continue;

		if ([record recordType] == recordType) {
			[result addObject: record];
			found = true;
		} else if ([record recordType] ==
		    OF_DNS_RESOURCE_RECORD_TYPE_CNAME) {
			[self resolveCNAME: record
				  response: response
				recordType: recordType
				 recursion: recursion
				    result: result];
			found = true;
		}
	}

	return found;
}

- (void)resolveCNAME: (OFCNAMEDNSResourceRecord *)CNAME
	    response: (OFDNSResponse *)response
	  recordType: (of_dns_resource_record_type_t)recordType
	   recursion: (unsigned int)recursion
	      result: (OFMutableArray *)result
{
	OFString *alias = CNAME.alias;
	bool found = false;

	if (recursion == 0)
		return;

	if ([self parseRecords: [response.answerRecords objectForKey: alias]
		      response: response
		    recordType: recordType
		     recursion: recursion - 1
			result: result])
		found = true;

	if ([self parseRecords: [response.additionalRecords objectForKey: alias]
		      response: response
		    recordType: recordType
		     recursion: recursion - 1
			result: result])
		found = true;

	if (!found) {
		of_run_loop_mode_t runLoopMode =
		    [OFRunLoop currentRunLoop].currentMode;
		OFNumber *recordTypeNumber =
		    [OFNumber numberWithInt: recordType];
		OFDNSQuery *query;

		_expectedResponses++;

		[result addObject:
		    [OFPair pairWithFirstObject: CNAME
				   secondObject: recordTypeNumber]];

		query = [OFDNSQuery
		    queryWithHost: alias
		      recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
		       recordType: recordType];
		[_resolver of_asyncPerformQuery: query
				       settings: nil
			       nameServersIndex: 0
			     searchDomainsIndex: 0
				    runLoopMode: runLoopMode
					 target: self
				       selector: @selector(resolver:
						     didResolveCNAME:response:
						     context:exception:)
					context: recordTypeNumber];
	}
}

-  (void)resolver: (OFDNSResolver *)resolver
  didResolveCNAME: (OFString *)CNAME
	 response: (OFDNSResponse *)response
	  context: (OFNumber *)context
	exception: (id)exception
{
	/*
	 * TODO: Error handling could be improved. Ignore error if there are
	 * responses, otherwise propagate error.
	 */

	of_dns_resource_record_type_t recordType = context.unsignedIntValue;
	bool found = false;
	OFMutableArray *records;
	size_t count;

	OF_ENSURE(resolver == _resolver);

	_expectedResponses--;

	if (exception != nil) {
		if (_expectedResponses == 0)
			[self done];

		return;
	}

	records = [OFMutableArray array];

	if ([self parseRecords: [response.answerRecords objectForKey: CNAME]
		      response: response
		    recordType: recordType
		     recursion: CNAME_RECURSION
			result: records])
		found = true;

	if ([self parseRecords: [response.additionalRecords objectForKey: CNAME]
		      response: response
		    recordType: recordType
		     recursion: CNAME_RECURSION
			result: records])
		found = true;

	if (!found) {
		if (_expectedResponses == 0)
			[self done];

		return;
	}

	count = _records.count;
	for (size_t i = 0; i < count; i++) {
		id object = [_records objectAtIndex: i];

		if (![object isKindOfClass: [OFPair class]])
			continue;

		if (![[[object firstObject] alias] isEqual: CNAME])
			continue;

		if ([[object secondObject] unsignedIntValue] != recordType)
			continue;

		[_records removeObjectAtIndex: i];
		[_records insertObjectsFromArray: records
					 atIndex: i];
		i += records.count - 1;
	}

	if (_expectedResponses == 0)
		[self done];
}

- (void)done
{
	OFMutableData *addresses =
	    [OFMutableData dataWithItemSize: sizeof(of_socket_address_t)];
	id exception = nil;

	for (id record in _records) {
		if (![record isKindOfClass: [OFDNSResourceRecord class]])
			continue;

		switch ([record recordType]) {
		case OF_DNS_RESOURCE_RECORD_TYPE_A:
		case OF_DNS_RESOURCE_RECORD_TYPE_AAAA:
			[addresses addItem: [record address]];
			break;
		default:
			break;
		}
	}

	[addresses makeImmutable];

	if (addresses.count == 0) {
		OFDNSQuery *query = [OFDNSQuery
		    queryWithHost: _host
		      recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
		       recordType: 0];

		exception = [OFDNSQueryFailedException
		    exceptionWithQuery: query
				 error: OF_DNS_RESOLVER_ERROR_UNKNOWN];
	}

	if ([_delegate respondsToSelector: @selector(
	    resolver:didResolveDomainName:socketAddresses:exception:)])
		[_delegate	resolver: _resolver
		    didResolveDomainName: _domainName
			 socketAddresses: (exception == nil ? addresses : nil)
			       exception: exception];
}

-	(void)resolver: (OFDNSResolver *)resolver
  didResolveDomainName: (OFString *)domainName
	      response: (OFDNSResponse *)response
	       context: (OFNumber *)context
	     exception: (id)exception
{
	/*
	 * TODO: Error handling could be improved. Ignore error if there are
	 * responses, otherwise propagate error.
	 */

	of_dns_resource_record_type_t recordType = context.unsignedIntValue;

	if (_resolver != nil)
		OF_ENSURE(resolver == _resolver);
	else
		_resolver = [resolver retain];

	_expectedResponses--;

	if (_domainName != nil) {
		if (![domainName isEqual: _domainName])
			/* Did the config change in between? */
			return;
	} else
		_domainName = [domainName copy];

	if (exception != nil) {
		if (_expectedResponses == 0)
			[self done];

		return;
	}

	[self parseRecords: [response.answerRecords objectForKey: _domainName]
		  response: response
		recordType: recordType
		 recursion: CNAME_RECURSION
		    result: _records];

	if (_expectedResponses == 0)
		[self done];
}
@end

@implementation OFDNSResolverResolveSocketAddressesDelegate
- (void)dealloc
{
	[_socketAddresses release];
	[_exception release];

	[super dealloc];
}

-	(void)resolver: (OFDNSResolver *)resolver
  didResolveDomainName: (OFString *)domainName
       socketAddresses: (OFData *)socketAddresses
	     exception: (id)exception
{
	_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())
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
}
#endif

+ (instancetype)resolver
{
	return [[[self alloc] init] autorelease];
}

- (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_asyncPerformQuery: (OFDNSQuery *)query
		    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 *resolverQuery;

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

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

	host = query.host;
	if (isFQDN(host, settings)) {
		domainName = host;

		if (![domainName hasSuffix: @"."])
			domainName = [domainName stringByAppendingString: @"."];
	} else {
		OFString *searchDomain = [settings->_searchDomains
		    objectAtIndex: searchDomainsIndex];

		domainName = [OFString stringWithFormat: @"%@.%@.",
		    host, searchDomain];
	}

	if (domainName.UTF8StringLength > 253)
		@throw [OFOutOfRangeException exception];

	resolverQuery = [[[OFDNSResolverQuery alloc]
		 initWithQuery: query
		    domainName: domainName
			    ID: ID
		      settings: settings
	      nameServersIndex: nameServersIndex
	    searchDomainsIndex: searchDomainsIndex
			target: target
		      selector: selector
		       context: context] autorelease];
	[_queries setObject: resolverQuery
		     forKey: ID];

	[self of_sendQuery: resolverQuery
	       runLoopMode: runLoopMode];

	objc_autoreleasePoolPop(pool);
}

-    (void)of_resolver: (OFDNSResolver *)resolver
  didResolveDomainName: (OFString *)domainName
	      response: (OFDNSResponse *)response
	       context: (id)delegate
	     exception: (id)exception
{
	if ([delegate respondsToSelector: @selector(resolver:
	    didResolveDomainName:response:exception:)])
		[delegate	resolver: resolver
		    didResolveDomainName: domainName
				response: response
			       exception: exception];
}

- (void)asyncPerformQuery: (OFDNSQuery *)query
		 delegate: (id <OFDNSResolverDelegate>)delegate
{
	[self of_asyncPerformQuery: query
			  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)asyncPerformQuery: (OFDNSQuery *)query
	      runLoopMode: (of_run_loop_mode_t)runLoopMode
		 delegate: (id <OFDNSResolverDelegate>)delegate
{
	[self of_asyncPerformQuery: query
			  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];
	[query->_cancelTimer release];
	query->_cancelTimer = nil;
	query->_cancelTimer = [[OFTimer alloc]
	    initWithFireDate: [OFDate dateWithTimeIntervalSinceNow:
				  query->_settings->_timeout]
		    interval: query->_settings->_timeout
		      target: self
		    selector: @selector(of_queryWithIDTimedOut:)
		      object: query
		     repeats: false];
	[[OFRunLoop currentRunLoop] addTimer: query->_cancelTimer
				     forMode: runLoopMode];

	nameServer = [query->_settings->_nameServers
	    objectAtIndex: query->_nameServersIndex];
	query->_usedNameServer = of_socket_address_parse_ip(nameServer, 53);

	switch (query->_usedNameServer.family) {
#ifdef OF_HAVE_IPV6
	case OF_SOCKET_ADDRESS_FAMILY_IPV6:
		if (_IPv6Socket == nil) {
			of_socket_address_t address =
			    of_socket_address_parse_ip(@"::", 0);

			_IPv6Socket = [[OFUDPSocket alloc] init];
			[_IPv6Socket of_bindToAddress: &address
					    extraType: SOCK_DNS];
			_IPv6Socket.blocking = false;
			_IPv6Socket.delegate = self;
			[_IPv6Socket asyncReceiveIntoBuffer: _buffer
						     length: BUFFER_LENGTH];
		}

		sock = _IPv6Socket;
		break;
#endif
	case OF_SOCKET_ADDRESS_FAMILY_IPV4:
		if (_IPv4Socket == nil) {
			of_socket_address_t address =
			    of_socket_address_parse_ip(@"0.0.0.0", 0);

			_IPv4Socket = [[OFUDPSocket alloc] init];
			[_IPv4Socket of_bindToAddress: &address
					    extraType: SOCK_DNS];
			_IPv4Socket.blocking = false;
			_IPv4Socket.delegate = self;
			[_IPv4Socket asyncReceiveIntoBuffer: _buffer
						     length: BUFFER_LENGTH];
		}

		sock = _IPv4Socket;
		break;
	default:
		@throw [OFInvalidArgumentException exception];
	}

	[sock asyncSendData: query->_queryData
		   receiver: &query->_usedNameServer
		runLoopMode: runLoopMode];
}

- (void)of_queryWithIDTimedOut: (OFDNSResolverQuery *)query
{
	OFDNSQueryFailedException *exception;

	if (query == nil)
		return;

	if (query->_nameServersIndex + 1 <
	    query->_settings->_nameServers.count) {
		query->_nameServersIndex++;
		[self of_sendQuery: query
		       runLoopMode: [OFRunLoop currentRunLoop].currentMode];
		return;
	}

	if (query->_attempt < query->_settings->_maxAttempts) {
		query->_attempt++;
		query->_nameServersIndex = 0;
		[self of_sendQuery: query
		       runLoopMode: [OFRunLoop currentRunLoop].currentMode];
		return;
	}

	query = [[query retain] autorelease];
	[_queries removeObjectForKey: query->_ID];

	/*
	 * Cancel any pending queries, to avoid a send being still pending and
	 * trying to access the query once it no longer exists.
	 */
	[_IPv4Socket cancelAsyncRequests];
	[_IPv4Socket asyncReceiveIntoBuffer: _buffer
				     length: BUFFER_LENGTH];
#ifdef OF_HAVE_IPV6
	[_IPv6Socket cancelAsyncRequests];
	[_IPv6Socket asyncReceiveIntoBuffer: _buffer
				     length: BUFFER_LENGTH];
#endif

	exception = [OFDNSQueryFailedException
	    exceptionWithQuery: query->_query
			 error: OF_DNS_RESOLVER_ERROR_TIMEOUT];

	callback(query->_target, query->_selector, self, query->_domainName,
	    nil, query->_context, exception);
}

-	  (bool)socket: (OFUDPSocket *)sock
  didReceiveIntoBuffer: (void *)buffer_
		length: (size_t)length
		sender: (const of_socket_address_t *)sender
	     exception: (id)exception
{
	unsigned char *buffer = buffer_;
	OFDictionary *answerRecords = nil, *authorityRecords = nil;
	OFDictionary *additionalRecords = nil;
	OFDNSResponse *response = nil;
	OFNumber *ID;
	OFDNSResolverQuery *query;

	if (exception != nil)
		return true;

	if (length < 2)
		/* We can't get the ID to get the query. Ignore packet. */
		return true;

	ID = [OFNumber numberWithUInt16: (buffer[0] << 8) | buffer[1]];
	query = [[[_queries objectForKey: ID] retain] autorelease];

	if (query == nil)
		return true;

	if (!of_socket_address_equal(sender, &query->_usedNameServer))
		return true;

	[query->_cancelTimer invalidate];
	[query->_cancelTimer release];
	query->_cancelTimer = nil;
	[_queries removeObjectForKey: ID];

	@try {
		bool tryNextNameServer = false;
		const unsigned char *queryDataBuffer;
		size_t i;
		of_dns_resolver_error_t error;
		uint16_t numQuestions, numAnswers, numAuthorityRecords;
		uint16_t numAdditionalRecords;

		if (length < 12)
			@throw [OFTruncatedDataException exception];

		if (query->_queryData.itemSize != 1 ||
		    query->_queryData.count < 12)
			@throw [OFInvalidArgumentException exception];

		queryDataBuffer = query->_queryData.items;

		/* QR */
		if ((buffer[2] & 0x80) == 0)
			@throw [OFInvalidServerReplyException exception];

		/* Opcode */
		if ((buffer[2] & 0x78) != (queryDataBuffer[2] & 0x78))
			@throw [OFInvalidServerReplyException exception];

		/* TC */
		if (buffer[2] & 0x02)
			@throw [OFTruncatedDataException exception];

		/* RCODE */
		switch (buffer[3] & 0x0F) {
		case 0:
			break;
		case 1:
			error = OF_DNS_RESOLVER_ERROR_SERVER_INVALID_FORMAT;
			break;
		case 2:
			error = OF_DNS_RESOLVER_ERROR_SERVER_FAILURE;
			tryNextNameServer = true;
			break;
		case 3:
			error = OF_DNS_RESOLVER_ERROR_SERVER_NAME_ERROR;
			break;
		case 4:
			error = OF_DNS_RESOLVER_ERROR_SERVER_NOT_IMPLEMENTED;
			tryNextNameServer = true;
			break;
		case 5:
			error = OF_DNS_RESOLVER_ERROR_SERVER_REFUSED;
			tryNextNameServer = true;
			break;
		default:
			error = OF_DNS_RESOLVER_ERROR_UNKNOWN;
			tryNextNameServer = true;
			break;
		}

		if (tryNextNameServer) {
			if (query->_searchDomainsIndex + 1 <
			    query->_settings->_searchDomains.count) {
				of_run_loop_mode_t runLoopMode =
				    [OFRunLoop currentRunLoop].currentMode;
				size_t nameServersIndex =
				    query->_nameServersIndex + 1;
				size_t searchDomainsIndex =
				    query->_searchDomainsIndex + 1;

				query->_searchDomainsIndex++;

				[self of_asyncPerformQuery: query->_query
						  settings: query->_settings
					  nameServersIndex: nameServersIndex
					searchDomainsIndex: searchDomainsIndex
					       runLoopMode: runLoopMode
						    target: query->_target
						  selector: query->_selector
						   context: query->_context];

				return true;
			}
		}

		if (buffer[3] & 0x0F)
			@throw [OFDNSQueryFailedException
			    exceptionWithQuery: query->_query
					 error: error];

		numQuestions = (buffer[4] << 8) | buffer[5];
		numAnswers = (buffer[6] << 8) | buffer[7];
		numAuthorityRecords = (buffer[8] << 8) | buffer[9];
		numAdditionalRecords = (buffer[10] << 8) | buffer[11];

		i = 12;

		/*
		 * Skip over the questions - we use the ID to identify the
		 * query.
		 *
		 * TODO: Compare to our query, just in case?
		 */
		for (uint_fast16_t j = 0; j < numQuestions; j++) {
			parseName(buffer, length, &i, MAX_ALLOWED_POINTERS);
			i += 4;
		}

		answerRecords = parseSection(buffer, length, &i, numAnswers);
		authorityRecords = parseSection(buffer, length, &i,
		    numAuthorityRecords);
		additionalRecords = parseSection(buffer, length, &i,
		    numAdditionalRecords);
		response = [OFDNSResponse
		    responseWithAnswerRecords: answerRecords
			     authorityRecords: authorityRecords
			    additionalRecords: additionalRecords];
	} @catch (id e) {
		callback(query->_target, query->_selector, self,
		    query->_domainName, nil, query->_context, e);
		return true;
	}

	callback(query->_target, query->_selector, self, query->_domainName,
	    response, query->_context, nil);

	return true;
}

- (void)asyncResolveSocketAddressesForHost: (OFString *)host
				  delegate: (id <OFDNSResolverDelegate>)delegate
{
	[self asyncResolveSocketAddressesForHost: host
				   addressFamily: OF_SOCKET_ADDRESS_FAMILY_ANY
				     runLoopMode: of_run_loop_mode_default
					delegate: delegate];
}

- (void)asyncResolveSocketAddressesForHost: (OFString *)host
			     addressFamily: (of_socket_address_family_t)
						addressFamily
				  delegate: (id <OFDNSResolverDelegate>)delegate
{
	[self asyncResolveSocketAddressesForHost: host
				   addressFamily: addressFamily
				     runLoopMode: of_run_loop_mode_default
					delegate: delegate];
}

- (void)asyncResolveSocketAddressesForHost: (OFString *)host
			     addressFamily: (of_socket_address_family_t)
						addressFamily
			       runLoopMode: (of_run_loop_mode_t)runLoopMode
				  delegate: (id <OFDNSResolverDelegate>)delegate
{
	OFArray OF_GENERIC(OFString *) *aliases;
	void *pool;
	OFDNSResolverAsyncResolveSocketAddressesContext *context;

	@try {
		of_socket_address_t address =
		    of_socket_address_parse_ip(host, 0);
		OFData *addresses = nil;
		id exception = nil;

		if (addressFamily == OF_SOCKET_ADDRESS_FAMILY_ANY ||
		    addressFamily == address.family)
			addresses = [OFData dataWithItems: &address
						 itemSize: sizeof(address)
						    count: 1];
		else
			exception = [OFInvalidArgumentException exception];

		if ([delegate respondsToSelector: @selector(resolver:
		    didResolveDomainName:socketAddresses:exception:)]) {
			OFTimer *timer = [OFTimer
			    timerWithTimeInterval: 0
					   target: delegate
					 selector: @selector(resolver:
						       didResolveDomainName:
						       socketAddresses:
						       exception:)
					   object: self
					   object: host
					   object: addresses
					   object: exception
					  repeats: false];
			[[OFRunLoop currentRunLoop] addTimer: timer
						     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;

			@try {
				address = of_socket_address_parse_ip(alias, 0);
			} @catch (OFInvalidFormatException *e) {
				continue;
			}

			if (addressFamily != OF_SOCKET_ADDRESS_FAMILY_ANY &&
			    address.family != addressFamily)
				continue;

			[addresses addItem: &address];
		}

		[addresses makeImmutable];

		if (addresses.count == 0) {
			of_dns_resource_record_type_t recordType = 0;

			addresses = nil;

			switch (addressFamily) {
			case OF_SOCKET_ADDRESS_FAMILY_ANY:
				recordType = OF_DNS_RESOURCE_RECORD_TYPE_ALL;
				break;
			case OF_SOCKET_ADDRESS_FAMILY_IPV4:
				recordType = OF_DNS_RESOURCE_RECORD_TYPE_A;
				break;
			case OF_SOCKET_ADDRESS_FAMILY_IPV6:
				recordType = OF_DNS_RESOURCE_RECORD_TYPE_AAAA;
				break;
			default:
				exception =
				    [OFInvalidArgumentException exception];
				break;
			}

			if (exception == nil) {
				of_dns_resource_record_class_t recordClass =
				    OF_DNS_RESOURCE_RECORD_CLASS_IN;
				of_dns_resolver_error_t error =
				    OF_DNS_RESOLVER_ERROR_NO_RESULT;
				OFDNSQuery *query = [OFDNSQuery
				    queryWithHost: host
				      recordClass: recordClass
				       recordType: recordType];

				exception = [OFDNSQueryFailedException
				    exceptionWithQuery: query
						 error: error];
			}
		}

		if ([delegate respondsToSelector: @selector(resolver:
		    didResolveDomainName:socketAddresses:exception:)]) {
			OFTimer *timer = [OFTimer
			    timerWithTimeInterval: 0
					   target: delegate
					 selector: @selector(resolver:
						       didResolveDomainName:
						       socketAddresses:
						       exception:)
					   object: self
					   object: host
					   object: addresses
					   object: exception
					  repeats: false];
			[[OFRunLoop currentRunLoop] addTimer: timer
						     forMode: runLoopMode];
		}

		return;
	}

	pool = objc_autoreleasePoolPush();

	context = [[[OFDNSResolverAsyncResolveSocketAddressesContext alloc]
	    initWithHost: host
		delegate: delegate] autorelease];

	switch (addressFamily) {
	case OF_SOCKET_ADDRESS_FAMILY_IPV4:
#ifdef OF_HAVE_IPV6
	case OF_SOCKET_ADDRESS_FAMILY_IPV6:
#endif
		context->_expectedResponses = 1;
		break;
	case OF_SOCKET_ADDRESS_FAMILY_ANY:
#ifdef OF_HAVE_IPV6
		context->_expectedResponses = 2;
#else
		context->_expectedResponses = 1;
#endif
		break;
	default:
		@throw [OFInvalidArgumentException exception];
	}

#ifdef OF_HAVE_IPV6
	if (addressFamily == OF_SOCKET_ADDRESS_FAMILY_IPV6 ||
	    addressFamily == OF_SOCKET_ADDRESS_FAMILY_ANY) {
		OFDNSQuery *query = [OFDNSQuery
		    queryWithHost: 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_asyncPerformQuery: query
				  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) {
		OFDNSQuery *query = [OFDNSQuery
		    queryWithHost: 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_asyncPerformQuery: query
				  settings: nil
			  nameServersIndex: 0
			searchDomainsIndex: 0
			       runLoopMode: runLoopMode
				    target: context
				  selector: @selector(resolver:
						didResolveDomainName:response:
						context:exception:)
				   context: recordTypeNumber];
	}

	objc_autoreleasePoolPop(pool);
}

- (OFData *)resolveSocketAddressesForHost: (OFString *)host
			    addressFamily: (of_socket_address_family_t)
					       addressFamily
{
	void *pool = objc_autoreleasePoolPush();
	OFRunLoop *runLoop = [OFRunLoop currentRunLoop];
	OFDNSResolverResolveSocketAddressesDelegate *delegate;
	OFData *ret;

	delegate = [[[OFDNSResolverResolveSocketAddressesDelegate
	    alloc] init] autorelease];

	[self asyncResolveSocketAddressesForHost: host
				   addressFamily: addressFamily
				     runLoopMode: resolveRunLoopMode
					delegate: delegate];

	while (!delegate->_done)
		[runLoop runMode: resolveRunLoopMode
		      beforeDate: nil];

	/* Cleanup */
	[runLoop runMode: resolveRunLoopMode
	      beforeDate: [OFDate date]];

	if (delegate->_exception != nil)
		@throw delegate->_exception;

	ret = [delegate->_socketAddresses retain];

	objc_autoreleasePoolPop(pool);

	return [ret autorelease];
}

- (void)close
{
	void *pool = objc_autoreleasePoolPush();
	OFEnumerator OF_GENERIC(OFDNSResolverQuery *) *enumerator;
	OFDNSResolverQuery *query;

	[_IPv4Socket cancelAsyncRequests];
	[_IPv4Socket release];
	_IPv4Socket = nil;

#ifdef OF_HAVE_IPV6
	[_IPv6Socket cancelAsyncRequests];
	[_IPv6Socket release];
	_IPv6Socket = nil;
#endif

	enumerator = [_queries objectEnumerator];
	while ((query = [enumerator nextObject]) != nil) {
		OFDNSQueryFailedException *exception;

		exception = [OFDNSQueryFailedException
		    exceptionWithQuery: query->_query
				 error: OF_DNS_RESOLVER_ERROR_CANCELED];

		callback(query->_target, query->_selector, self,
		    query->_domainName, nil, query->_context, exception);
	}

	[_queries removeAllObjects];

	objc_autoreleasePoolPop(pool);
}
@end