ObjFW  Check-in [507d999b53]

#import "OFString.h"
#import "OFDNSResourceRecord.h"

OF_ASSUME_NONNULL_BEGIN

@class OFArray OF_GENERIC(ObjectType);
@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

	OF_DNS_RESOLVER_ERROR_SERVER_REFUSED
} of_dns_resolver_error_t;

/*!
 * @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.
 */
@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;
	size_t _minNumberOfDotsInAbsoluteName;
	bool _usesTCP;
	of_time_interval_t _configReloadInterval;
	OFDate *_lastConfigReload;
	OFUDPSocket *_IPv4Socket;
#ifdef OF_HAVE_IPV6
	OFUDPSocket *_IPv6Socket;
#endif
	OFMutableDictionary OF_GENERIC(OFNumber *, OFDNSResolverQuery *)
	    *_queries;
}

@property (nonatomic) size_t 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.

#include <string.h>
#include "unistd_wrapper.h"

#import "OFDNSResolver.h"
#import "OFArray.h"
#import "OFCharacterSet.h"
#import "OFData.h"
#import "OFDate.h"
#import "OFDictionary.h"
#import "OFFile.h"
#import "OFLocale.h"
#import "OFNumber.h"
#import "OFString.h"
#import "OFTimer.h"
#import "OFUDPSocket.h"

 * 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 TIMEOUT 2
#define ATTEMPTS 3

#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"
# define RESOLV_CONF_PATH @"DEVS:Internet/resolv.conf"
#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

/*
 * TODO:
 *
 *  - Resolve with each search domain
 *  - Fallback to TCP
 */

	       searchDomains: (OFArray OF_GENERIC(OFString *) *)searchDomains
		      target: (id)target
		    selector: (SEL)selector
		     context: (id)context;
@end

@interface OFDNSResolver ()
- (void)of_parseConfig;
#ifdef OF_HAVE_FILES
- (void)of_parseHosts: (OFString *)path;
# ifndef OF_WINDOWS
- (void)of_parseResolvConf: (OFString *)path;
- (void)of_parseResolvConfOption: (OFString *)option;
# endif
#endif
#ifdef OF_WINDOWS
- (void)of_parseNetworkParams;
#endif
- (void)of_reloadConfig;
- (void)of_sendQuery: (OFDNSResolverQuery *)query;
- (void)of_queryWithIDTimedOut: (OFDNSResolverQuery *)query;
- (size_t)of_socket: (OFUDPSocket *)sock
      didSendBuffer: (void **)buffer
	  bytesSent: (size_t)bytesSent
	   receiver: (of_socket_address_t *)receiver
	    context: (OFDNSResolverQuery *)query

}
@end

@implementation OFDNSResolver
@synthesize staticHosts = _staticHosts, nameServers = _nameServers;
@synthesize localDomain = _localDomain, searchDomains = _searchDomains;
@synthesize minNumberOfDotsInAbsoluteName = _minNumberOfDotsInAbsoluteName;
@synthesize usesTCP = _usesTCP, configReloadInterval = _configReloadInterval;

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

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

	@try {




		_queries = [[OFMutableDictionary alloc] init];











		[self of_parseConfig];





























































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

	return self;
}

- (void)of_parseConfig
{
	void *pool = objc_autoreleasePoolPush();
#ifdef OF_WINDOWS
	OFString *path;
#endif

	_minNumberOfDotsInAbsoluteName = 1;
	_usesTCP = false;
	_configReloadInterval = 2;

#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 of_parseHosts: path];
# endif

	[self of_parseNetworkParams];
#elif defined(OF_HAVE_FILES)
	[self of_parseHosts: HOSTS_PATH];
# ifdef OF_OPENBSD
	[self of_parseHosts: @"/etc/resolv.conf.tail"];
# endif

	[self of_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

	if (_localDomain == nil)
		_localDomain = [domainFromHostname() copy];

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

	_lastConfigReload = [[OFDate alloc] init];

	objc_autoreleasePoolPop(pool);
}

- (void)dealloc
{
	[self close];

	[_staticHosts release];
	[_nameServers release];
	[_localDomain release];
	[_searchDomains release];
	[_lastConfigReload release];
	[_IPv4Socket release];
#ifdef OF_HAVE_IPV6
	[_IPv6Socket release];
#endif
	[_queries release];

	[super dealloc];
}

#ifdef OF_HAVE_FILES
- (void)of_parseHosts: (OFString *)path
{

	if ([localDomain length] > 0)
		_localDomain = [localDomain copy];

	objc_autoreleasePoolPop(pool);
}
#endif

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

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

	[_staticHosts release];
	_staticHosts = nil;

	[_nameServers release];
	_nameServers = nil;

	[_localDomain release];
	_localDomain = nil;

	[_searchDomains release];
	_searchDomains = nil;

	_minNumberOfDotsInAbsoluteName = 1;
	_usesTCP = false;
	_configReloadInterval = 2;

	[_lastConfigReload release];
	_lastConfigReload = nil;

	[self of_parseConfig];
}

- (void)asyncResolveHost: (OFString *)host
		  target: (id)target
		selector: (SEL)selector
		 context: (id)context
{
	[self asyncResolveHost: host

		selector: (SEL)selector
		 context: (id)context
{
	void *pool = objc_autoreleasePoolPush();
	OFNumber *ID;
	OFString *domainName;
	OFDNSResolverQuery *query;

	[self of_reloadConfig];

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

	if ([host hasSuffix: @"."])

		recordType = of_dns_resource_record_type_parse(
		    [arguments objectAtIndex: 1]);

	if ([arguments count] >= 3)
		recordClass = of_dns_resource_record_class_parse(
		    [arguments objectAtIndex: 2]);

	if ([arguments count] >= 4) {
		[resolver setConfigReloadInterval: 0];
		[resolver setNameServers:
		    [OFArray arrayWithObject: [arguments objectAtIndex: 3]]];
	}

	[resolver asyncResolveHost: [arguments objectAtIndex: 0]
		       recordClass: recordClass
			recordType: recordType
			    target: self
			  selector: @selector(DNSResolver:didResolveDomainName:
					answerRecords:authorityRecords:
					additionalRecords:context:exception:)
			   context: nil];
}
@end