ObjFW  Check-in [8555d64ee6]

- (void)asyncResolveHost: (OFString *)host
	     recordClass: (of_dns_resource_record_class_t)recordClass
	      recordType: (of_dns_resource_record_type_t)recordType
		  target: (id)target
		selector: (SEL)selector
		 context: (nullable id)context;

/*!
 * @brief Asynchronously resolves the specified host to socket addresses.
 *
 * @param host The host to resolve
 * @param target The target to call with the result once resolving is done
 * @param selector The selector to call on the target. The signature must be
 *		   the following:
 *		   @parblock
 *
 *		       void (OFDNSResolver *resolver, OFString *domainName,
 *		           OFData *_Nullable, socketAddresses,
 *		           id _Nullable context, id _Nullable exception)
 *
 *		   `resolver` is the acting resolver.@n
 *		   `domainName` is the fully qualified domain name used to
 *		   resolve the host.@n
 *		   `socketAddresses` is OFData containing several
 *		   of_socket_address_t.@n
 *		   `context` is the context object originally passed.@n
 *		   `exception` is an exception that happened during resolving,
 *		   otherwise nil.
 *		   @endparblock
 * @param context A context object to pass along to the target
 */
- (void)asyncResolveSocketAddressesForHost: (OFString *)host
				    target: (id)target
				  selector: (SEL)selector
				   context: (nullable id)context;

/*!
 * @brief Asynchronously resolves the specified host to socket addresses.
 *
 * @param host The host to resolve
 * @param addressFamily The desired socket address family
 * @param target The target to call with the result once resolving is done
 * @param selector The selector to call on the target. The signature must be
 *		   the following:
 *		   @parblock
 *
 *		       void (OFDNSResolver *resolver, OFString *domainName,
 *		           OFData *_Nullable socketAddresses,
 *		           id _Nullable context, id _Nullable exception)
 *
 *		   `resolver` is the acting resolver.@n
 *		   `domainName` is the fully qualified domain name used to
 *		   resolve the host.@n
 *		   `socketAddresses` is OFData containing several
 *		   of_socket_address_t.@n
 *		   `context` is the context object originally passed.@n
 *		   `exception` is an exception that happened during resolving,
 *		   otherwise nil.
 *		   @endparblock
 * @param context A context object to pass along to the target
 */
- (void)asyncResolveSocketAddressesForHost: (OFString *)host
			     addressFamily: (of_socket_address_family_t)
						addressFamily
				    target: (id)target
				  selector: (SEL)selector
				   context: (nullable id)context;

/*!
 * @brief Closes all sockets and cancels all ongoing requests.
 */
- (void)close;
@end

OF_ASSUME_NONNULL_END

		    settings: (OFDNSResolverSettings *)settings
	    nameServersIndex: (size_t)nameServersIndex
	  searchDomainsIndex: (size_t)searchDomainsIndex
		      target: (id)target
		    selector: (SEL)selector
		     context: (id)context;
@end

@interface OFDNSResolver_ResolveSocketAddressContext: OFObject
{
	OFString *_host;
	id _target;
	SEL _selector;
	id _context;
	OFMutableArray OF_GENERIC(OF_KINDOF(OFDNSResourceRecord *)) *_records;
@public
	unsigned int _expectedResponses;
}

- (instancetype)initWithHost: (OFString *)host
		      target: (id)target
		    selector: (SEL)selector
		     context: (id)context;
-	(void)resolver: (OFDNSResolver *)resolver
  didResolveDomainName: (OFString *)domainName
	 answerRecords: (OFArray *)answerRecords
      authorityRecords: (OFArray *)authorityRecords
     additionalRecords: (OFArray *)additionalRecords
	       context: (id)context
	     exception: (id)exception;
@end

@interface OFDNSResolver ()
- (void)of_setDefaults;
- (void)of_obtainSystemConfig;
#if defined(OF_HAVE_FILES) && !defined(OF_NINTENDO_3DS)
- (void)of_parseHosts: (OFString *)path;
# if !defined(OF_WINDOWS) && !defined(OF_AMIGAOS4)

	[_settings release];
	[_target release];
	[_context release];
	[_queryData release];
	[_cancelTimer release];

	[super dealloc];
}
@end

@implementation OFDNSResolver_ResolveSocketAddressContext
- (instancetype)initWithHost: (OFString *)host
		      target: (id)target
		    selector: (SEL)selector
		     context: (id)context
{
	self = [super init];

	@try {
		_host = [host copy];
		_target = [target retain];
		_selector = selector;
		_context = [context retain];

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

	return self;
}

- (void)dealloc
{
	[_host release];
	[_target release];
	[_context release];
	[_records release];

	[super dealloc];
}

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

	of_socket_address_family_t addressFamily = [context intValue];

	_expectedResponses--;

	if (exception == nil) {
		for (OFDNSResourceRecord *record in answerRecords) {
			if (![[record name] isEqual: domainName])
				continue;

			if ([record recordClass] !=
			    OF_DNS_RESOURCE_RECORD_CLASS_IN)
				continue;

			switch ([record recordType]) {
			case OF_DNS_RESOURCE_RECORD_TYPE_A:
				if (addressFamily ==
				    OF_SOCKET_ADDRESS_FAMILY_IPV4 ||
				    addressFamily ==
				    OF_SOCKET_ADDRESS_FAMILY_ANY)
					[_records addObject: record];

				break;
			case OF_DNS_RESOURCE_RECORD_TYPE_AAAA:
				if (addressFamily ==
				    OF_SOCKET_ADDRESS_FAMILY_IPV6 ||
				    addressFamily ==
				    OF_SOCKET_ADDRESS_FAMILY_ANY)
					[_records addObject: record];

				break;
			/*
			 * TODO: Add CNAMEs and replace them with addresses in
			 *	 a later stage.
			 */
			default:
				break;
			}
		}
	}

	if (_expectedResponses == 0) {
		void (*method)(id, SEL, OFDNSResolver *, OFString *, OFData *,
		    id, id) = (void (*)(id, SEL, OFDNSResolver *, OFString *,
		    OFData *, id, id))[_target methodForSelector: _selector];
		OFMutableData *addresses = nil;

		if ([_records count] > 0) {
			addresses = [OFMutableData
			    dataWithItemSize: sizeof(of_socket_address_t)
				    capacity: [_records count]];

			for (OF_KINDOF(OFDNSResourceRecord *) record in
			    _records)
				[addresses addItem: [record address]];

			[addresses makeImmutable];

			method(_target, _selector, resolver, domainName,
			    addresses, _context, nil);
		} else {
			OFResolveHostFailedException *e;

			e = [OFResolveHostFailedException
			    exceptionWithHost: _host
				  recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
				   recordType: 0
					error: OF_DNS_RESOLVER_ERROR_UNKNOWN];

			method(_target, _selector, resolver, domainName, nil,
			    _context, e);
		}
	}
}
@end

@implementation OFDNSResolver
@synthesize staticHosts = _staticHosts, nameServers = _nameServers;
@synthesize localDomain = _localDomain, searchDomains = _searchDomains;
@synthesize timeout = _timeout, maxAttempts = _maxAttempts;

	callback(query->_target, query->_selector, self, query->_domainName,
	    answerRecords, authorityRecords, additionalRecords,
	    query->_context, nil);

	return false;
}

- (void)asyncResolveSocketAddressesForHost: (OFString *)host
				    target: (id)target
				  selector: (SEL)selector
				   context: (nullable id)context
{
#ifdef OF_HAVE_IPV6
	[self asyncResolveSocketAddressesForHost: host
				   addressFamily: OF_SOCKET_ADDRESS_FAMILY_ANY
					  target: target
					selector: selector
					 context: context];
#else
	[self asyncResolveSocketAddressesForHost: host
				   addressFamily: OF_SOCKET_ADDRESS_FAMILY_IPV4
					  target: target
					selector: selector
					 context: context];
#endif
}

- (void)asyncResolveSocketAddressesForHost: (OFString *)host
			     addressFamily: (of_socket_address_family_t)
						addressFamily
				    target: (id)target
				  selector: (SEL)selector
				   context: (id)userContext
{
	void *pool = objc_autoreleasePoolPush();
	OFDNSResolver_ResolveSocketAddressContext *context;
	OFNumber *addressFamilyNumber;

	context = [[[OFDNSResolver_ResolveSocketAddressContext alloc]
	    initWithHost: host
		  target: target
		selector: selector
		 context: userContext] autorelease];

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

	addressFamilyNumber = [OFNumber numberWithInt: addressFamily];

	if (addressFamily == OF_SOCKET_ADDRESS_FAMILY_IPV6 ||
	    addressFamily == OF_SOCKET_ADDRESS_FAMILY_ANY)
		[self asyncResolveHost: host
			   recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
			    recordType: OF_DNS_RESOURCE_RECORD_TYPE_AAAA
				target: context
			      selector: @selector(resolver:didResolveDomainName:
					    answerRecords:authorityRecords:
					    additionalRecords:context:
					    exception:)
			       context: addressFamilyNumber];

	if (addressFamily == OF_SOCKET_ADDRESS_FAMILY_IPV4 ||
	    addressFamily == OF_SOCKET_ADDRESS_FAMILY_ANY)
		[self asyncResolveHost: host
			   recordClass: OF_DNS_RESOURCE_RECORD_CLASS_IN
			    recordType: OF_DNS_RESOURCE_RECORD_TYPE_A
				target: context
			      selector: @selector(resolver:didResolveDomainName:
					    answerRecords:authorityRecords:
					    additionalRecords:context:
					    exception:)
			       context: addressFamilyNumber];

	objc_autoreleasePoolPop(pool);
}

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

typedef u8 sa_family_t;
#endif

/*!
 * @brief A socket address family.
 */
typedef enum {
	/** An unknown address family. */
	OF_SOCKET_ADDRESS_FAMILY_UNKNOWN,
	/** IPv4 */
	OF_SOCKET_ADDRESS_FAMILY_IPV4,
	/** IPv6 */
	OF_SOCKET_ADDRESS_FAMILY_IPV6,
	/** Any address family */
	OF_SOCKET_ADDRESS_FAMILY_ANY = 255
} of_socket_address_family_t;

#ifndef OF_HAVE_IPV6
struct sockaddr_in6 {
	sa_family_t sin6_family;
	in_port_t sin6_port;
	uint32_t sin6_flowinfo;