packages/multicast_dns/lib/src/resource_record.dart - mirrors/packages - Git at Google

 // Copyright 2018 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';

 import 'package:meta/meta.dart';
 import 'package:multicast_dns/src/constants.dart';
 import 'package:multicast_dns/src/packet.dart';

 // TODO(dnfield): Probably should go with a real hashing function here
 // when https://github.com/dart-lang/sdk/issues/11617 is figured out.
 const int _seedHashPrime = 2166136261;
 const int _multipleHashPrime = 16777619;

 int _combineHash(int current, int hash) =>
     (current & _multipleHashPrime) ^ hash;

 int _hashValues(List<int> values) {
   assert(values != null);
   assert(values.isNotEmpty);

   return values.fold(
     _seedHashPrime,
     (int current, int next) => _combineHash(current, next),
   );
 }

 /// Enumeration of support resource record types.
 class ResourceRecordType {
   // This class is intended to be used as a namespace, and should not be
   // extended directly.
   factory ResourceRecordType._() => null;

   /// An IPv4 Address record, also known as an "A" record. It has a value of 1.
   static const int addressIPv4 = 1;

   /// An IPv6 Address record, also known as an "AAAA" record.  It has a vaule of
   /// 28.
   static const int addressIPv6 = 28;

   /// An IP Address reverse map record, also known as a "PTR" recored. It has a
   /// value of 12.
   static const int serverPointer = 12;

   /// An available service record, also known as an "SRV" record.  It has a
   /// value of 33.
   static const int service = 33;

   /// A text record, also known as a "TXT" record.  It has a value of 16.
   static const int text = 16;

   // TODO(dnfield): Support ANY in some meaningful way.  Might be server only.
   // /// A query for all records of all types known to the name server.
   // static const int any = 255;

   /// Checks that a given int is a valid ResourceRecordType.
   ///
   /// This method is intended to be called only from an `assert()`.
   static bool debugAssertValid(int resourceRecordType) {
     return resourceRecordType == addressIPv4 ||
         resourceRecordType == addressIPv6 ||
         resourceRecordType == serverPointer ||
         resourceRecordType == service ||
         resourceRecordType == text;
   }

   /// Prints a debug-friendly version of the resource record type value.
   static String toDebugString(int resourceRecordType) {
     switch (resourceRecordType) {
       case addressIPv4:
         return 'A (IPv4 Address)';
       case addressIPv6:
         return 'AAAA (IPv6 Address)';
       case serverPointer:
         return 'PTR (Domain Name Pointer)';
       case service:
         return 'SRV (Service record)';
       case text:
         return 'TXT (Text)';
     }
     return 'Unknown ($resourceRecordType)';
   }
 }

 /// Represents a DNS query.
 class ResourceRecordQuery {
   /// Creates a new ResourceRecordQuery.
   ///
   /// Most callers should prefer one of the named constructors.
   ResourceRecordQuery(
     this.resourceRecordType,
     this.fullyQualifiedName,
     this.questionType,
   )   : assert(fullyQualifiedName != null),
         assert(ResourceRecordType.debugAssertValid(resourceRecordType));

   /// An A (IPv4) query.
   ResourceRecordQuery.addressIPv4(
     String name, {
     bool isMulticast = true,
   }) : this(
           ResourceRecordType.addressIPv4,
           name,
           isMulticast ? QuestionType.multicast : QuestionType.unicast,
         );

   /// An AAAA (IPv6) query.
   ResourceRecordQuery.addressIPv6(
     String name, {
     bool isMulticast = true,
   }) : this(
           ResourceRecordType.addressIPv6,
           name,
           isMulticast ? QuestionType.multicast : QuestionType.unicast,
         );

   /// A PTR (Server pointer) query.
   ResourceRecordQuery.serverPointer(
     String name, {
     bool isMulticast = true,
   }) : this(
           ResourceRecordType.serverPointer,
           name,
           isMulticast ? QuestionType.multicast : QuestionType.unicast,
         );

   /// An SRV (Service) query.
   ResourceRecordQuery.service(
     String name, {
     bool isMulticast = true,
   }) : this(
           ResourceRecordType.service,
           name,
           isMulticast ? QuestionType.multicast : QuestionType.unicast,
         );

   /// A TXT (Text record) query.
   ResourceRecordQuery.text(
     String name, {
     bool isMulticast = true,
   }) : this(
           ResourceRecordType.text,
           name,
           isMulticast ? QuestionType.multicast : QuestionType.unicast,
         );

   /// Tye type of resource record - one of [ResourceRecordType]'s values.
   final int resourceRecordType;

   /// The Fully Qualified Domain Name associated with the request.
   final String fullyQualifiedName;

   /// The [QuestionType], i.e. multicast or unicast.
   final int questionType;

   /// Convenience accessor to determine whether the question type is multicast.
   bool get isMulticast => questionType == QuestionType.multicast;

   /// Convenience accessor to determine whether the question type is unicast.
   bool get isUnicast => questionType == QuestionType.unicast;

   /// Encodes this query to the raw wire format.
   List<int> encode() {
     return encodeMDnsQuery(
       fullyQualifiedName,
       type: resourceRecordType,
       multicast: isMulticast,
     );
   }

   @override
   int get hashCode => _hashValues(
       <int>[resourceRecordType, fullyQualifiedName.hashCode, questionType]);

   @override
   bool operator ==(Object other) {
     return other is ResourceRecordQuery &&
         other.resourceRecordType == resourceRecordType &&
         other.fullyQualifiedName == fullyQualifiedName &&
         other.questionType == questionType;
   }

   @override
   String toString() =>
       '$runtimeType{$fullyQualifiedName, type: ${ResourceRecordType.toDebugString(resourceRecordType)}, isMulticast: $isMulticast}';
 }

 /// Base implementation of DNS resource records (RRs).
 abstract class ResourceRecord {
   /// Creates a new ResourceRecord.
   const ResourceRecord(this.resourceRecordType, this.name, this.validUntil)
       : assert(name != null);

   /// The FQDN for this record.
   final String name;

   /// The epoch time at which point this record is valid for in the cache.
   final int validUntil;

   /// The raw resource record value.  See [ResourceRecordType] for supported values.
   final int resourceRecordType;

   String get _additionalInfo;

   @override
   String toString() =>
       '$runtimeType{$name, validUntil: ${DateTime.fromMillisecondsSinceEpoch(validUntil ?? 0)}, $_additionalInfo}';

   @override
   bool operator ==(Object other) {
     return other.runtimeType == runtimeType && _equals(other);
   }

   @protected
   bool _equals(ResourceRecord other) {
     return other.name == name &&
         other.validUntil == validUntil &&
         other.resourceRecordType == resourceRecordType;
   }

   @override
   int get hashCode {
     return _hashValues(<int>[
       name.hashCode,
       validUntil.hashCode,
       resourceRecordType.hashCode,
       _hashCode,
     ]);
   }

   // Subclasses of this class should use _hashValues to create a hash code
   // that will then get hashed in with the common values on this class.
   @protected
   int get _hashCode;

   /// Low level method for encoding this record into an mDNS packet.
   ///
   /// Subclasses should provide the packet format of their encapsulated data
   /// into a `Uint8List`, which could then be used to write a pakcet to send
   /// as a response for this record type.
   Uint8List encodeResponseRecord();
 }

 /// A Service Pointer for reverse mapping an IP address (DNS "PTR").
 class PtrResourceRecord extends ResourceRecord {
   /// Creates a new PtrResourceRecord.
   PtrResourceRecord(
     String name,
     int validUntil, {
     @required this.domainName,
   })  : assert(domainName != null),
         super(ResourceRecordType.serverPointer, name, validUntil);

   /// The FQDN for this record.
   final String domainName;

   @override
   String get _additionalInfo => 'domainName: $domainName';

   @override
   bool _equals(ResourceRecord other) {
     return other is PtrResourceRecord &&
         other.domainName == domainName &&
         super._equals(other);
   }

   @override
   int get _hashCode => _combineHash(_seedHashPrime, domainName.hashCode);

   @override
   Uint8List encodeResponseRecord() {
     return Uint8List.fromList(utf8.encode(domainName));
   }
 }

 /// An IP Address record for IPv4 (DNS "A") or IPv6 (DNS "AAAA") records.
 class IPAddressResourceRecord extends ResourceRecord {
   /// Creates a new IPAddressResourceRecord.
   IPAddressResourceRecord(
     String name,
     int validUntil, {
     @required this.address,
   }) : super(
             address.type == InternetAddressType.IPv4
                 ? ResourceRecordType.addressIPv4
                 : ResourceRecordType.addressIPv6,
             name,
             validUntil);

   /// The [InternetAddress] for this record.
   final InternetAddress address;

   @override
   String get _additionalInfo => 'address: $address';

   @override
   bool _equals(ResourceRecord other) {
     return other is IPAddressResourceRecord && other.address == address;
   }

   @override
   int get _hashCode => _combineHash(_seedHashPrime, address.hashCode);

   @override
   Uint8List encodeResponseRecord() {
     return Uint8List.fromList(address.rawAddress);
   }
 }

 /// A Service record, capturing a host target and port (DNS "SRV").
 class SrvResourceRecord extends ResourceRecord {
   /// Creates a new service record.
   SrvResourceRecord(
     String name,
     int validUntil, {
     @required this.target,
     @required this.port,
     @required this.priority,
     @required this.weight,
   })  : assert(target != null),
         assert(port != null),
         assert(priority != null),
         assert(weight != null),
         super(ResourceRecordType.service, name, validUntil);

   /// The hostname for this record.
   final String target;

   /// The port for this record.
   final int port;

   /// The relative priority of this service.
   final int priority;

   /// The weight (used when multiple services have the same priority).
   final int weight;

   @override
   String get _additionalInfo =>
       'target: $target, port: $port, priority: $priority, weight: $weight';

   @override
   bool _equals(ResourceRecord other) {
     return other is SrvResourceRecord &&
         other.target == target &&
         other.port == port &&
         other.priority == priority &&
         other.weight == weight;
   }

   @override
   int get _hashCode => _hashValues(<int>[
         target.hashCode,
         port.hashCode,
         priority.hashCode,
         weight.hashCode,
       ]);

   @override
   Uint8List encodeResponseRecord() {
     final List<int> data = utf8.encode(target);
     final Uint8List result = Uint8List(data.length + 7);
     final ByteData resultData = ByteData.view(result.buffer);
     resultData.setUint16(0, priority);
     resultData.setUint16(2, weight);
     resultData.setUint16(4, port);
     result[6] = data.length;
     return result..setRange(7, data.length, data);
   }
 }

 /// A Text record, contianing additional textual data (DNS "TXT").
 class TxtResourceRecord extends ResourceRecord {
   /// Creates a new text record.
   TxtResourceRecord(
     String name,
     int validUntil, {
     @required this.text,
   })  : assert(text != null),
         super(ResourceRecordType.text, name, validUntil);

   /// The raw text from this record.
   final String text;

   @override
   String get _additionalInfo => 'text: $text';

   @override
   bool _equals(ResourceRecord other) {
     return other is TxtResourceRecord && other.text == text;
   }

   @override
   int get _hashCode => _combineHash(_seedHashPrime, text.hashCode);

   @override
   Uint8List encodeResponseRecord() {
     return Uint8List.fromList(utf8.encode(text));
   }
 }
	// Copyright 2018 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:convert';
	import 'dart:io';
	import 'dart:typed_data';

	import 'package:meta/meta.dart';
	import 'package:multicast_dns/src/constants.dart';
	import 'package:multicast_dns/src/packet.dart';

	// TODO(dnfield): Probably should go with a real hashing function here
	// when https://github.com/dart-lang/sdk/issues/11617 is figured out.
	const int _seedHashPrime = 2166136261;
	const int _multipleHashPrime = 16777619;

	int _combineHash(int current, int hash) =>
	(current & _multipleHashPrime) ^ hash;

	int _hashValues(List<int> values) {
	assert(values != null);
	assert(values.isNotEmpty);

	return values.fold(
	_seedHashPrime,
	(int current, int next) => _combineHash(current, next),
	);
	}

	/// Enumeration of support resource record types.
	class ResourceRecordType {
	// This class is intended to be used as a namespace, and should not be
	// extended directly.
	factory ResourceRecordType._() => null;

	/// An IPv4 Address record, also known as an "A" record. It has a value of 1.
	static const int addressIPv4 = 1;

	/// An IPv6 Address record, also known as an "AAAA" record. It has a vaule of
	/// 28.
	static const int addressIPv6 = 28;

	/// An IP Address reverse map record, also known as a "PTR" recored. It has a
	/// value of 12.
	static const int serverPointer = 12;

	/// An available service record, also known as an "SRV" record. It has a
	/// value of 33.
	static const int service = 33;

	/// A text record, also known as a "TXT" record. It has a value of 16.
	static const int text = 16;

	// TODO(dnfield): Support ANY in some meaningful way. Might be server only.
	// /// A query for all records of all types known to the name server.
	// static const int any = 255;

	/// Checks that a given int is a valid ResourceRecordType.
	///
	/// This method is intended to be called only from an `assert()`.
	static bool debugAssertValid(int resourceRecordType) {
	return resourceRecordType == addressIPv4 \|\|
	resourceRecordType == addressIPv6 \|\|
	resourceRecordType == serverPointer \|\|
	resourceRecordType == service \|\|
	resourceRecordType == text;
	}

	/// Prints a debug-friendly version of the resource record type value.
	static String toDebugString(int resourceRecordType) {
	switch (resourceRecordType) {
	case addressIPv4:
	return 'A (IPv4 Address)';
	case addressIPv6:
	return 'AAAA (IPv6 Address)';
	case serverPointer:
	return 'PTR (Domain Name Pointer)';
	case service:
	return 'SRV (Service record)';
	case text:
	return 'TXT (Text)';
	}
	return 'Unknown ($resourceRecordType)';
	}
	}

	/// Represents a DNS query.
	class ResourceRecordQuery {
	/// Creates a new ResourceRecordQuery.
	///
	/// Most callers should prefer one of the named constructors.
	ResourceRecordQuery(
	this.resourceRecordType,
	this.fullyQualifiedName,
	this.questionType,
	) : assert(fullyQualifiedName != null),
	assert(ResourceRecordType.debugAssertValid(resourceRecordType));

	/// An A (IPv4) query.
	ResourceRecordQuery.addressIPv4(
	String name, {
	bool isMulticast = true,
	}) : this(
	ResourceRecordType.addressIPv4,
	name,
	isMulticast ? QuestionType.multicast : QuestionType.unicast,
	);

	/// An AAAA (IPv6) query.
	ResourceRecordQuery.addressIPv6(
	String name, {
	bool isMulticast = true,
	}) : this(
	ResourceRecordType.addressIPv6,
	name,
	isMulticast ? QuestionType.multicast : QuestionType.unicast,
	);

	/// A PTR (Server pointer) query.
	ResourceRecordQuery.serverPointer(
	String name, {
	bool isMulticast = true,
	}) : this(
	ResourceRecordType.serverPointer,
	name,
	isMulticast ? QuestionType.multicast : QuestionType.unicast,
	);

	/// An SRV (Service) query.
	ResourceRecordQuery.service(
	String name, {
	bool isMulticast = true,
	}) : this(
	ResourceRecordType.service,
	name,
	isMulticast ? QuestionType.multicast : QuestionType.unicast,
	);

	/// A TXT (Text record) query.
	ResourceRecordQuery.text(
	String name, {
	bool isMulticast = true,
	}) : this(
	ResourceRecordType.text,
	name,
	isMulticast ? QuestionType.multicast : QuestionType.unicast,
	);

	/// Tye type of resource record - one of [ResourceRecordType]'s values.
	final int resourceRecordType;

	/// The Fully Qualified Domain Name associated with the request.
	final String fullyQualifiedName;

	/// The [QuestionType], i.e. multicast or unicast.
	final int questionType;

	/// Convenience accessor to determine whether the question type is multicast.
	bool get isMulticast => questionType == QuestionType.multicast;

	/// Convenience accessor to determine whether the question type is unicast.
	bool get isUnicast => questionType == QuestionType.unicast;

	/// Encodes this query to the raw wire format.
	List<int> encode() {
	return encodeMDnsQuery(
	fullyQualifiedName,
	type: resourceRecordType,
	multicast: isMulticast,
	);
	}

	@override
	int get hashCode => _hashValues(
	<int>[resourceRecordType, fullyQualifiedName.hashCode, questionType]);

	@override
	bool operator ==(Object other) {
	return other is ResourceRecordQuery &&
	other.resourceRecordType == resourceRecordType &&
	other.fullyQualifiedName == fullyQualifiedName &&
	other.questionType == questionType;
	}

	@override
	String toString() =>
	'$runtimeType{$fullyQualifiedName, type: ${ResourceRecordType.toDebugString(resourceRecordType)}, isMulticast: $isMulticast}';
	}

	/// Base implementation of DNS resource records (RRs).
	abstract class ResourceRecord {
	/// Creates a new ResourceRecord.
	const ResourceRecord(this.resourceRecordType, this.name, this.validUntil)
	: assert(name != null);

	/// The FQDN for this record.
	final String name;

	/// The epoch time at which point this record is valid for in the cache.
	final int validUntil;

	/// The raw resource record value. See [ResourceRecordType] for supported values.
	final int resourceRecordType;

	String get _additionalInfo;

	@override
	String toString() =>
	'$runtimeType{$name, validUntil: ${DateTime.fromMillisecondsSinceEpoch(validUntil ?? 0)}, $_additionalInfo}';

	@override
	bool operator ==(Object other) {
	return other.runtimeType == runtimeType && _equals(other);
	}

	@protected
	bool _equals(ResourceRecord other) {
	return other.name == name &&
	other.validUntil == validUntil &&
	other.resourceRecordType == resourceRecordType;
	}

	@override
	int get hashCode {
	return _hashValues(<int>[
	name.hashCode,
	validUntil.hashCode,
	resourceRecordType.hashCode,
	_hashCode,
	]);
	}

	// Subclasses of this class should use _hashValues to create a hash code
	// that will then get hashed in with the common values on this class.
	@protected
	int get _hashCode;

	/// Low level method for encoding this record into an mDNS packet.
	///
	/// Subclasses should provide the packet format of their encapsulated data
	/// into a `Uint8List`, which could then be used to write a pakcet to send
	/// as a response for this record type.
	Uint8List encodeResponseRecord();
	}

	/// A Service Pointer for reverse mapping an IP address (DNS "PTR").
	class PtrResourceRecord extends ResourceRecord {
	/// Creates a new PtrResourceRecord.
	PtrResourceRecord(
	String name,
	int validUntil, {
	@required this.domainName,
	}) : assert(domainName != null),
	super(ResourceRecordType.serverPointer, name, validUntil);

	/// The FQDN for this record.
	final String domainName;

	@override
	String get _additionalInfo => 'domainName: $domainName';

	@override
	bool _equals(ResourceRecord other) {
	return other is PtrResourceRecord &&
	other.domainName == domainName &&
	super._equals(other);
	}

	@override
	int get _hashCode => _combineHash(_seedHashPrime, domainName.hashCode);

	@override
	Uint8List encodeResponseRecord() {
	return Uint8List.fromList(utf8.encode(domainName));
	}
	}

	/// An IP Address record for IPv4 (DNS "A") or IPv6 (DNS "AAAA") records.
	class IPAddressResourceRecord extends ResourceRecord {
	/// Creates a new IPAddressResourceRecord.
	IPAddressResourceRecord(
	String name,
	int validUntil, {
	@required this.address,
	}) : super(
	address.type == InternetAddressType.IPv4
	? ResourceRecordType.addressIPv4
	: ResourceRecordType.addressIPv6,
	name,
	validUntil);

	/// The [InternetAddress] for this record.
	final InternetAddress address;

	@override
	String get _additionalInfo => 'address: $address';

	@override
	bool _equals(ResourceRecord other) {
	return other is IPAddressResourceRecord && other.address == address;
	}

	@override
	int get _hashCode => _combineHash(_seedHashPrime, address.hashCode);

	@override
	Uint8List encodeResponseRecord() {
	return Uint8List.fromList(address.rawAddress);
	}
	}

	/// A Service record, capturing a host target and port (DNS "SRV").
	class SrvResourceRecord extends ResourceRecord {
	/// Creates a new service record.
	SrvResourceRecord(
	String name,
	int validUntil, {
	@required this.target,
	@required this.port,
	@required this.priority,
	@required this.weight,
	}) : assert(target != null),
	assert(port != null),
	assert(priority != null),
	assert(weight != null),
	super(ResourceRecordType.service, name, validUntil);

	/// The hostname for this record.
	final String target;

	/// The port for this record.
	final int port;

	/// The relative priority of this service.
	final int priority;

	/// The weight (used when multiple services have the same priority).
	final int weight;

	@override
	String get _additionalInfo =>
	'target: $target, port: $port, priority: $priority, weight: $weight';

	@override
	bool _equals(ResourceRecord other) {
	return other is SrvResourceRecord &&
	other.target == target &&
	other.port == port &&
	other.priority == priority &&
	other.weight == weight;
	}

	@override
	int get _hashCode => _hashValues(<int>[
	target.hashCode,
	port.hashCode,
	priority.hashCode,
	weight.hashCode,
	]);

	@override
	Uint8List encodeResponseRecord() {
	final List<int> data = utf8.encode(target);
	final Uint8List result = Uint8List(data.length + 7);
	final ByteData resultData = ByteData.view(result.buffer);
	resultData.setUint16(0, priority);
	resultData.setUint16(2, weight);
	resultData.setUint16(4, port);
	result[6] = data.length;
	return result..setRange(7, data.length, data);
	}
	}

	/// A Text record, contianing additional textual data (DNS "TXT").
	class TxtResourceRecord extends ResourceRecord {
	/// Creates a new text record.
	TxtResourceRecord(
	String name,
	int validUntil, {
	@required this.text,
	}) : assert(text != null),
	super(ResourceRecordType.text, name, validUntil);

	/// The raw text from this record.
	final String text;

	@override
	String get _additionalInfo => 'text: $text';

	@override
	bool _equals(ResourceRecord other) {
	return other is TxtResourceRecord && other.text == text;
	}

	@override
	int get _hashCode => _combineHash(_seedHashPrime, text.hashCode);

	@override
	Uint8List encodeResponseRecord() {
	return Uint8List.fromList(utf8.encode(text));
	}
	}