/*
* Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3.0 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* version 3.0 for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* version 3.0 along with this program. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#import "OFHostAddressResolver.h"
#import "OFArray.h"
#import "OFDNSResolver.h"
#import "OFDNSResolverSettings.h"
#import "OFData.h"
#import "OFDate.h"
#import "OFDictionary.h"
#import "OFRunLoop.h"
#import "OFString.h"
#import "OFTimer.h"
#import "OFDNSQueryFailedException.h"
#import "OFInvalidArgumentException.h"
#import "OFInvalidFormatException.h"
#import "OFResolveHostFailedException.h"
@interface OFHostAddressResolverDelegate: OFObject <OFDNSResolverHostDelegate>
{
@public
bool _done;
OFData *_addresses;
id _exception;
}
@end
static const OFRunLoopMode resolveRunLoopMode =
@"OFHostAddressResolverResolveRunLoopMode";
static bool
isFQDN(OFString *host, unsigned int minNumberOfDotsInAbsoluteName)
{
const char *UTF8String;
size_t length;
unsigned int dots;
if ([host hasSuffix: @"."])
return true;
UTF8String = host.UTF8String;
length = host.UTF8StringLength;
dots = 0;
for (size_t i = 0; i < length; i++)
if (UTF8String[i] == '.')
dots++;
return (dots >= minNumberOfDotsInAbsoluteName);
}
static bool
addressForRecord(OF_KINDOF(OFDNSResourceRecord *) record,
const OFSocketAddress **address, OFSocketAddressFamily addressFamily)
{
switch ([record recordType]) {
#ifdef OF_HAVE_IPV6
case OFDNSRecordTypeAAAA:
if (addressFamily != OFSocketAddressFamilyIPv6 &&
addressFamily != OFSocketAddressFamilyAny)
return false;
break;
#endif
case OFDNSRecordTypeA:
if (addressFamily != OFSocketAddressFamilyIPv4 &&
addressFamily != OFSocketAddressFamilyAny)
return false;
break;
default:
return false;
}
*address = [record address];
return true;
}
static void
callDelegateInMode(OFRunLoopMode runLoopMode,
id <OFDNSResolverHostDelegate> delegate, OFDNSResolver *resolver,
OFString *host, OFData *addresses, id exception)
{
SEL selector = @selector(resolver:didResolveHost:addresses:exception:);
if ([delegate respondsToSelector: selector]) {
OFTimer *timer = [OFTimer
timerWithTimeInterval: 0
target: delegate
selector: selector
object: resolver
object: host
object: addresses
object: exception
repeats: false];
[[OFRunLoop currentRunLoop] addTimer: timer
forMode: runLoopMode];
}
}
@implementation OFHostAddressResolver
- (instancetype)initWithHost: (OFString *)host
addressFamily: (OFSocketAddressFamily)addressFamily
resolver: (OFDNSResolver *)resolver
settings: (OFDNSResolverSettings *)settings
runLoopMode: (OFRunLoopMode)runLoopMode
delegate: (id <OFDNSResolverHostDelegate>)delegate
{
self = [super init];
@try {
_host = [host copy];
_addressFamily = addressFamily;
_resolver = [resolver retain];
_settings = [settings copy];
_runLoopMode = [runLoopMode copy];
_delegate = [delegate retain];
} @catch (id e) {
[self release];
@throw e;
}
return self;
}
- (void)dealloc
{
[_host release];
[_resolver release];
[_settings release];
[_runLoopMode release];
[_delegate release];
[_addresses release];
[super dealloc];
}
- (void)sendQueries
{
OFString *domainName;
if (!_isFQDN) {
OFString *searchDomain = @"";
if (_searchDomainIndex < _settings->_searchDomains.count)
searchDomain = [_settings->_searchDomains
objectAtIndex: _searchDomainIndex];
domainName = [OFString stringWithFormat: @"%@.%@",
_host, searchDomain];
} else
domainName = _host;
#ifdef OF_HAVE_IPV6
if (_addressFamily == OFSocketAddressFamilyIPv6 ||
_addressFamily == OFSocketAddressFamilyAny) {
OFDNSQuery *query = [OFDNSQuery
queryWithDomainName: domainName
DNSClass: OFDNSClassIN
recordType: OFDNSRecordTypeAAAA];
_numExpectedResponses++;
[_resolver asyncPerformQuery: query
runLoopMode: _runLoopMode
delegate: self];
}
#endif
if (_addressFamily == OFSocketAddressFamilyIPv4 ||
_addressFamily == OFSocketAddressFamilyAny) {
OFDNSQuery *query = [OFDNSQuery
queryWithDomainName: domainName
DNSClass: OFDNSClassIN
recordType: OFDNSRecordTypeA];
_numExpectedResponses++;
[_resolver asyncPerformQuery: query
runLoopMode: _runLoopMode
delegate: self];
}
}
- (void)resolver: (OFDNSResolver *)resolver
didPerformQuery: (OFDNSQuery *)query
response: (OFDNSResponse *)response
exception: (id)exception
{
_numExpectedResponses--;
if ([exception isKindOfClass: [OFDNSQueryFailedException class]] &&
[exception errorCode] == OFDNSResolverErrorCodeServerNameError &&
!_isFQDN && _numExpectedResponses == 0 && _addresses.count == 0 &&
_searchDomainIndex + 1 < _settings->_searchDomains.count) {
_searchDomainIndex++;
[self sendQueries];
return;
}
for (OF_KINDOF(OFDNSResourceRecord *) record in
[response.answerRecords objectForKey: query.domainName]) {
const OFSocketAddress *address = NULL;
OFDNSQuery *CNAMEQuery;
if ([record DNSClass] != OFDNSClassIN)
continue;
if (addressForRecord(record, &address, _addressFamily)) {
[_addresses addItem: address];
continue;
}
if ([record recordType] != OFDNSRecordTypeCNAME)
continue;
/* FIXME: Check if it's already in answers */
CNAMEQuery = [OFDNSQuery queryWithDomainName: [record alias]
DNSClass: OFDNSClassIN
recordType: query.recordType];
_numExpectedResponses++;
[_resolver asyncPerformQuery: CNAMEQuery
runLoopMode: _runLoopMode
delegate: self];
}
if (_numExpectedResponses > 0)
return;
[_addresses makeImmutable];
if (_addresses.count == 0) {
[_addresses release];
_addresses = nil;
if ([exception isKindOfClass:
[OFDNSQueryFailedException class]])
exception = [OFResolveHostFailedException
exceptionWithHost: _host
addressFamily: _addressFamily
errorCode: [exception errorCode]];
if (exception == nil)
exception = [OFResolveHostFailedException
exceptionWithHost: _host
addressFamily: _addressFamily
errorCode: OFDNSResolverErrorCodeNoResult];
} else
exception = nil;
if ([_delegate respondsToSelector:
@selector(resolver:didResolveHost:addresses:exception:)])
[_delegate resolver: _resolver
didResolveHost: _host
addresses: _addresses
exception: exception];
}
- (void)asyncResolve
{
void *pool = objc_autoreleasePoolPush();
OFArray OF_GENERIC(OFString *) *aliases;
@try {
OFSocketAddress address = OFSocketAddressParseIP(_host, 0);
OFData *addresses = nil;
id exception = nil;
if (_addressFamily == address.family ||
_addressFamily == OFSocketAddressFamilyAny)
addresses = [OFData dataWithItems: &address
count: 1
itemSize: sizeof(address)];
else
exception = [OFInvalidArgumentException exception];
callDelegateInMode(_runLoopMode, _delegate, _resolver, _host,
addresses, exception);
objc_autoreleasePoolPop(pool);
return;
} @catch (OFInvalidFormatException *e) {
}
if ((aliases = [_settings->_staticHosts objectForKey:
_host.lowercaseString]) != nil) {
OFMutableData *addresses = [OFMutableData
dataWithItemSize: sizeof(OFSocketAddress)];
id exception = nil;
for (OFString *alias in aliases) {
OFSocketAddress address;
@try {
address = OFSocketAddressParseIP(alias, 0);
} @catch (OFInvalidFormatException *e) {
continue;
}
if (_addressFamily != address.family &&
_addressFamily != OFSocketAddressFamilyAny)
continue;
[addresses addItem: &address];
}
[addresses makeImmutable];
if (addresses.count == 0) {
addresses = nil;
exception = [OFResolveHostFailedException
exceptionWithHost: _host
addressFamily: _addressFamily
errorCode: OFDNSResolverErrorCodeNoResult];
}
callDelegateInMode(_runLoopMode, _delegate, _resolver, _host,
addresses, exception);
objc_autoreleasePoolPop(pool);
return;
}
_isFQDN = isFQDN(_host, _settings->_minNumberOfDotsInAbsoluteName);
_addresses = [[OFMutableData alloc]
initWithItemSize: sizeof(OFSocketAddress)];
[self sendQueries];
objc_autoreleasePoolPop(pool);
}
- (OFData *)resolve
{
void *pool = objc_autoreleasePoolPush();
OFRunLoop *runLoop = [OFRunLoop currentRunLoop];
OFHostAddressResolverDelegate *delegate;
OFData *ret;
delegate = [[[OFHostAddressResolverDelegate alloc] init] autorelease];
_runLoopMode = [resolveRunLoopMode copy];
_delegate = [delegate retain];
[self asyncResolve];
while (!delegate->_done)
[runLoop runMode: resolveRunLoopMode beforeDate: nil];
/* Cleanup */
[runLoop runMode: resolveRunLoopMode beforeDate: [OFDate date]];
if (delegate->_exception != nil)
@throw delegate->_exception;
ret = [delegate->_addresses copy];
objc_autoreleasePoolPop(pool);
return [ret autorelease];
}
@end
@implementation OFHostAddressResolverDelegate
- (void)dealloc
{
[_addresses release];
[_exception release];
[super dealloc];
}
- (void)resolver: (OFDNSResolver *)resolver
didResolveHost: (OFString *)host
addresses: (OFData *)addresses
exception: (id)exception
{
_addresses = [addresses copy];
_exception = [exception retain];
_done = true;
}
@end