Feature/mqttv5 subscriptions server (#1246)

* Add support for RetainHandling. * Add support for No Local. * Add support for _SubscriptionIdentifier_. * Add more Unit Tests. * Update docs.
2026-10-22 04:43:04 +08:00 · 2021-09-23 20:30:43 +02:00
parent feb53e78c6
commit c756a4092f
83 changed files with 2032 additions and 1237 deletions
@@ -8,6 +8,7 @@ using MQTTnet.Client.Unsubscribing;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
+using MQTTnet.Server.Internal;

 namespace MQTTnet.Formatter
 {
@@ -15,13 +16,13 @@ namespace MQTTnet.Formatter
    {
        MqttApplicationMessage CreateApplicationMessage(MqttPublishPacket publishPacket);

-        MqttClientAuthenticateResult CreateClientConnectResult(MqttConnAckPacket connAckPacket);
+        MqttClientConnectResult CreateClientConnectResult(MqttConnAckPacket connAckPacket);

        MqttClientPublishResult CreateClientPublishResult(MqttPubAckPacket pubAckPacket);

        MqttClientPublishResult CreateClientPublishResult(MqttPubRecPacket pubRecPacket, MqttPubCompPacket pubCompPacket);
        
-        Client.Subscribing.MqttClientSubscribeResult CreateClientSubscribeResult(MqttSubscribePacket subscribePacket, MqttSubAckPacket subAckPacket);
+        MqttClientSubscribeResult CreateClientSubscribeResult(MqttSubscribePacket subscribePacket, MqttSubAckPacket subAckPacket);
        
        MqttClientUnsubscribeResult CreateClientUnsubscribeResult(MqttUnsubscribePacket unsubscribePacket, MqttUnsubAckPacket unsubAckPacket);

@@ -41,7 +42,7 @@ namespace MQTTnet.Formatter
        
        MqttSubscribePacket CreateSubscribePacket(MqttClientSubscribeOptions options);

-        MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, Server.MqttClientSubscribeResult subscribeResult);
+        MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, SubscribeResult subscribeResult);

        MqttUnsubscribePacket CreateUnsubscribePacket(MqttClientUnsubscribeOptions options);

@@ -11,7 +11,7 @@ using MQTTnet.Server;
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using MqttClientSubscribeResult = MQTTnet.Client.Subscribing.MqttClientSubscribeResult;
+using MQTTnet.Server.Internal;

 namespace MQTTnet.Formatter.V3
 {
@@ -85,12 +85,12 @@ namespace MQTTnet.Formatter.V3
            };
        }

-        public MqttClientAuthenticateResult CreateClientConnectResult(MqttConnAckPacket connAckPacket)
+        public MqttClientConnectResult CreateClientConnectResult(MqttConnAckPacket connAckPacket)
        {
            if (connAckPacket == null) throw new ArgumentNullException(nameof(connAckPacket));

            MqttClientConnectResultCode resultCode;
-            switch (connAckPacket.ReturnCode.Value)
+            switch (connAckPacket.ReturnCode)
            {
                case MqttConnectReturnCode.ConnectionAccepted:
                    {
@@ -132,8 +132,10 @@ namespace MQTTnet.Formatter.V3
                    throw new MqttProtocolViolationException("Received unexpected return code.");
            }

-            return new MqttClientAuthenticateResult
+            return new MqttClientConnectResult
            {
+                RetainAvailable = true, // Always true because v3.1.1 does not have a way to "disable" that feature.
+                WildcardSubscriptionAvailable = true, // Always true because v3.1.1 does not have a way to "disable" that feature.
                IsSessionPresent = connAckPacket.IsSessionPresent,
                ResultCode = resultCode
            };
@@ -205,7 +207,7 @@ namespace MQTTnet.Formatter.V3
            return subscribePacket;
        }

-        public MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, Server.MqttClientSubscribeResult subscribeResult)
+        public MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, SubscribeResult subscribeResult)
        {
            if (subscribePacket == null) throw new ArgumentNullException(nameof(subscribePacket));
            if (subscribeResult == null) throw new ArgumentNullException(nameof(subscribeResult));
@@ -1,5 +1,6 @@
 using System;
 using System.Linq;
+using System.Net;
 using System.Runtime.CompilerServices;
 using MQTTnet.Adapter;
 using MQTTnet.Exceptions;
@@ -407,7 +408,7 @@ namespace MQTTnet.Formatter.V3
        protected virtual byte EncodeConnAckPacket(MqttConnAckPacket packet, IMqttPacketWriter packetWriter)
        {
            packetWriter.Write(0); // Reserved.
-            packetWriter.Write((byte)packet.ReturnCode.Value);
+            packetWriter.Write((byte)packet.ReturnCode);

            return MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.ConnAck);
        }
@@ -520,6 +521,21 @@ namespace MQTTnet.Formatter.V3
            {
                foreach (var topicFilter in packet.TopicFilters)
                {
+                    if (topicFilter.NoLocal)
+                    {
+                        throw new MqttProtocolViolationException("NoLocal is not supported in 3.1.1.");
+                    }
+
+                    if (topicFilter.RetainAsPublished)
+                    {
+                        throw new MqttProtocolViolationException("RetainAsPublished is not supported in 3.1.1.");
+                    }
+                    
+                    if (topicFilter.RetainHandling != MqttRetainHandling.SendAtSubscribe)
+                    {
+                        throw new MqttProtocolViolationException("RetainHandling is not supported in 3.1.1.");
+                    }
+                    
                    packetWriter.WriteWithLengthPrefix(topicFilter.Topic);
                    packetWriter.Write((byte)topicFilter.QualityOfServiceLevel);
                }
@@ -11,7 +11,7 @@ using MQTTnet.Server;
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using MqttClientSubscribeResult = MQTTnet.Client.Subscribing.MqttClientSubscribeResult;
+using MQTTnet.Server.Internal;

 namespace MQTTnet.Formatter.V5
 {
@@ -115,16 +115,16 @@ namespace MQTTnet.Formatter.V5
            };
        }

-        public MqttClientAuthenticateResult CreateClientConnectResult(MqttConnAckPacket connAckPacket)
+        public MqttClientConnectResult CreateClientConnectResult(MqttConnAckPacket connAckPacket)
        {
            if (connAckPacket == null) throw new ArgumentNullException(nameof(connAckPacket));

-            return new MqttClientAuthenticateResult
+            return new MqttClientConnectResult
            {
                IsSessionPresent = connAckPacket.IsSessionPresent,
-                ResultCode = (MqttClientConnectResultCode)(int)(connAckPacket.ReasonCode ?? 0),
-                WildcardSubscriptionAvailable = connAckPacket.Properties?.WildcardSubscriptionAvailable,
-                RetainAvailable = connAckPacket.Properties?.RetainAvailable,
+                ResultCode = (MqttClientConnectResultCode)(int)connAckPacket.ReasonCode,
+                WildcardSubscriptionAvailable = connAckPacket.Properties?.WildcardSubscriptionAvailable ?? true,
+                RetainAvailable = connAckPacket.Properties?.RetainAvailable ?? true,
                AssignedClientIdentifier = connAckPacket.Properties?.AssignedClientIdentifier,
                AuthenticationMethod = connAckPacket.Properties?.AuthenticationMethod,
                AuthenticationData = connAckPacket.Properties?.AuthenticationData,
@@ -133,13 +133,13 @@ namespace MQTTnet.Formatter.V5
                ReceiveMaximum = connAckPacket.Properties?.ReceiveMaximum,
                MaximumQoS = connAckPacket.Properties?.MaximumQoS ?? MqttQualityOfServiceLevel.ExactlyOnce,
                ResponseInformation = connAckPacket.Properties?.ResponseInformation,
-                TopicAliasMaximum = connAckPacket.Properties?.TopicAliasMaximum,
+                TopicAliasMaximum = connAckPacket.Properties?.TopicAliasMaximum ?? 0,
                ServerReference = connAckPacket.Properties?.ServerReference,
                ServerKeepAlive = connAckPacket.Properties?.ServerKeepAlive,
                SessionExpiryInterval = connAckPacket.Properties?.SessionExpiryInterval,
-                SubscriptionIdentifiersAvailable = connAckPacket.Properties?.SubscriptionIdentifiersAvailable,
-                SharedSubscriptionAvailable = connAckPacket.Properties?.SharedSubscriptionAvailable,
-                UserProperties = connAckPacket.Properties?.UserProperties
+                SubscriptionIdentifiersAvailable = connAckPacket.Properties?.SubscriptionIdentifiersAvailable ?? true,
+                SharedSubscriptionAvailable = connAckPacket.Properties?.SharedSubscriptionAvailable ?? true,
+                UserProperties = connAckPacket.Properties?.UserProperties ?? new List<MqttUserProperty>()
            };
        }

@@ -180,12 +180,18 @@ namespace MQTTnet.Formatter.V5
                ReasonCode = connectionValidatorContext.ReasonCode,
                Properties = new MqttConnAckPacketProperties
                {
+                    RetainAvailable = true,
+                    SubscriptionIdentifiersAvailable = true,
+                    SharedSubscriptionAvailable = false,
+                    TopicAliasMaximum = ushort.MaxValue,
+                    WildcardSubscriptionAvailable = true,
+                    
                    UserProperties = connectionValidatorContext.ResponseUserProperties,
                    AuthenticationMethod = connectionValidatorContext.AuthenticationMethod,
                    AuthenticationData = connectionValidatorContext.ResponseAuthenticationData,
                    AssignedClientIdentifier = connectionValidatorContext.AssignedClientIdentifier,
                    ReasonString = connectionValidatorContext.ReasonString,
-                    TopicAliasMaximum = ushort.MaxValue
+                    ServerReference = connectionValidatorContext.ServerReference
                }
            };
        }
@@ -242,7 +248,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        public MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, Server.MqttClientSubscribeResult subscribeResult)
+        public MqttSubAckPacket CreateSubAckPacket(MqttSubscribePacket subscribePacket, SubscribeResult subscribeResult)
        {
            if (subscribePacket == null) throw new ArgumentNullException(nameof(subscribePacket));
            if (subscribeResult == null) throw new ArgumentNullException(nameof(subscribeResult));
@@ -9,9 +9,9 @@ namespace MQTTnet.Formatter.V5
 {
    public class MqttV500PacketDecoder
    {
-        private static readonly MqttPingReqPacket PingReqPacket = new MqttPingReqPacket();
+        static readonly MqttPingReqPacket PingReqPacket = new MqttPingReqPacket();

-        private static readonly MqttPingRespPacket PingRespPacket = new MqttPingRespPacket();
+        static readonly MqttPingRespPacket PingRespPacket = new MqttPingRespPacket();

        public MqttBasePacket Decode(ReceivedMqttPacket receivedMqttPacket)
        {
@@ -45,7 +45,7 @@ namespace MQTTnet.Formatter.V5
            }
        }

-        private static MqttBasePacket DecodeConnectPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeConnectPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -214,7 +214,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeConnAckPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeConnAckPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -225,15 +225,17 @@ namespace MQTTnet.Formatter.V5
                IsSessionPresent = (acknowledgeFlags & 0x1) > 0,
                ReasonCode = (MqttConnectReasonCode)body.ReadByte()
            };
+            
+            // Set all default values according to specification. When they are missing the often
+            // indicate that a feature is available.
+            packet.Properties.RetainAvailable = true;
+            packet.Properties.SharedSubscriptionAvailable = true;
+            packet.Properties.SubscriptionIdentifiersAvailable = true;
+            packet.Properties.WildcardSubscriptionAvailable = true;

            var propertiesReader = new MqttV500PropertiesReader(body);
            while (propertiesReader.MoveNext())
            {
-                if (packet.Properties == null)
-                {
-                    packet.Properties = new MqttConnAckPacketProperties();
-                }
-
                if (propertiesReader.CurrentPropertyId == MqttPropertyId.SessionExpiryInterval)
                {
                    packet.Properties.SessionExpiryInterval = propertiesReader.ReadSessionExpiryInterval();
@@ -316,7 +318,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeDisconnectPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeDisconnectPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -363,7 +365,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeSubscribePacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeSubscribePacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -422,7 +424,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeSubAckPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeSubAckPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -467,7 +469,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeUnsubscribePacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeUnsubscribePacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -507,7 +509,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeUnsubAckPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeUnsubAckPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -552,17 +554,17 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodePingReqPacket()
+        static MqttBasePacket DecodePingReqPacket()
        {
            return PingReqPacket;
        }

-        private static MqttBasePacket DecodePingRespPacket()
+        static MqttBasePacket DecodePingRespPacket()
        {
            return PingRespPacket;
        }

-        private static MqttBasePacket DecodePublishPacket(byte header, IMqttPacketBodyReader body)
+        static MqttBasePacket DecodePublishPacket(byte header, IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -647,7 +649,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodePubAckPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodePubAckPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -694,7 +696,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodePubRecPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodePubRecPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -741,7 +743,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodePubRelPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodePubRelPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -788,7 +790,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodePubCompPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodePubCompPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -835,7 +837,7 @@ namespace MQTTnet.Formatter.V5
            return packet;
        }

-        private static MqttBasePacket DecodeAuthPacket(IMqttPacketBodyReader body)
+        static MqttBasePacket DecodeAuthPacket(IMqttPacketBodyReader body)
        {
            ThrowIfBodyIsEmpty(body);

@@ -888,7 +890,7 @@ namespace MQTTnet.Formatter.V5
        }

        // ReSharper disable once ParameterOnlyUsedForPreconditionCheck.Local
-        private static void ThrowIfBodyIsEmpty(IMqttPacketBodyReader body)
+        static void ThrowIfBodyIsEmpty(IMqttPacketBodyReader body)
        {
            if (body == null || body.Length == 0)
            {
@@ -173,12 +173,7 @@ namespace MQTTnet.Formatter.V5
        {
            if (packet == null) throw new ArgumentNullException(nameof(packet));
            if (packetWriter == null) throw new ArgumentNullException(nameof(packetWriter));
-
-            if (!packet.ReasonCode.HasValue)
-            {
-                ThrowReasonCodeNotSetException();
-            }
-
+            
            byte connectAcknowledgeFlags = 0x0;
            if (packet.IsSessionPresent)
            {
@@ -186,7 +181,7 @@ namespace MQTTnet.Formatter.V5
            }

            packetWriter.Write(connectAcknowledgeFlags);
-            packetWriter.Write((byte)packet.ReasonCode.Value);
+            packetWriter.Write((byte)packet.ReasonCode);

            var propertiesWriter = new MqttV500PropertiesWriter();
            if (packet.Properties != null)
@@ -247,19 +242,18 @@ namespace MQTTnet.Formatter.V5
            var propertiesWriter = new MqttV500PropertiesWriter();
            if (packet.Properties != null)
            {
-                if (packet.Properties.TopicAlias == 0)
-                {
-                    throw new MqttProtocolViolationException("A Topic Alias of 0 is not permitted. A sender MUST NOT send a PUBLISH packet containing a Topic Alias which has the value 0 [MQTT-3.3.2-8].");
-                }
-
                propertiesWriter.WriteContentType(packet.Properties.ContentType);
                propertiesWriter.WriteCorrelationData(packet.Properties.CorrelationData);
                propertiesWriter.WriteMessageExpiryInterval(packet.Properties.MessageExpiryInterval);
                propertiesWriter.WritePayloadFormatIndicator(packet.Properties.PayloadFormatIndicator);
                propertiesWriter.WriteResponseTopic(packet.Properties.ResponseTopic);
                propertiesWriter.WriteSubscriptionIdentifiers(packet.Properties.SubscriptionIdentifiers);
-                propertiesWriter.WriteTopicAlias(packet.Properties.TopicAlias);
                propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
+
+                if (packet.Properties.TopicAlias > 0)
+                {
+                    propertiesWriter.WriteTopicAlias(packet.Properties.TopicAlias);
+                }
            }

            propertiesWriter.WriteTo(packetWriter);
@@ -411,7 +405,11 @@ namespace MQTTnet.Formatter.V5
            var propertiesWriter = new MqttV500PropertiesWriter();
            if (packet.Properties != null)
            {
-                propertiesWriter.WriteSubscriptionIdentifier(packet.Properties.SubscriptionIdentifier);
+                if (packet.Properties.SubscriptionIdentifier > 0)
+                {
+                    propertiesWriter.WriteSubscriptionIdentifier(packet.Properties.SubscriptionIdentifier);
+                }
+
                propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
            }

@@ -425,19 +423,19 @@ namespace MQTTnet.Formatter.V5

                    var options = (byte)topicFilter.QualityOfServiceLevel;

-                    if (topicFilter.NoLocal == true)
+                    if (topicFilter.NoLocal)
                    {
                        options |= 1 << 2;
                    }

-                    if (topicFilter.RetainAsPublished == true)
+                    if (topicFilter.RetainAsPublished)
                    {
                        options |= 1 << 3;
                    }

-                    if (topicFilter.RetainHandling.HasValue)
+                    if (topicFilter.RetainHandling != MqttRetainHandling.SendAtSubscribe)
                    {
-                        options |= (byte)((byte)topicFilter.RetainHandling.Value << 4);
+                        options |= (byte)((byte)topicFilter.RetainHandling << 4);
                    }
                    
                    packetWriter.Write(options);
@@ -74,12 +74,12 @@ namespace MQTTnet.Formatter.V5
            WriteAsFourByteInteger(MqttPropertyId.SessionExpiryInterval, value);
        }

-        public void WriteSubscriptionIdentifier(uint? value)
+        public void WriteSubscriptionIdentifier(uint value)
        {
            WriteAsVariableLengthInteger(MqttPropertyId.SubscriptionIdentifier, value);
        }

-        public void WriteSubscriptionIdentifiers(IEnumerable<uint> value)
+        public void WriteSubscriptionIdentifiers(ICollection<uint> value)
        {
            if (value == null)
            {
@@ -148,9 +148,15 @@ namespace MQTTnet.Formatter.V5
            WriteAsFourByteInteger(MqttPropertyId.MaximumPacketSize, value);
        }

-        public void WriteRetainAvailable(bool? value)
+        public void WriteRetainAvailable(bool value)
        {
-            Write(MqttPropertyId.RetainAvailable, value);
+            if (value)
+            {
+                // Absence of the flag means it is supported! 
+                return;
+            }
+            
+            Write(MqttPropertyId.RetainAvailable, false);
        }

        public void WriteAssignedClientIdentifier(string value)
@@ -168,14 +174,26 @@ namespace MQTTnet.Formatter.V5
            Write(MqttPropertyId.WildcardSubscriptionAvailable, value);
        }

-        public void WriteSubscriptionIdentifiersAvailable(bool? value)
+        public void WriteSubscriptionIdentifiersAvailable(bool value)
        {
-            Write(MqttPropertyId.SubscriptionIdentifiersAvailable, value);
+            if (value)
+            {
+                // Absence of the flag means it is supported! 
+                return;
+            }
+            
+            Write(MqttPropertyId.SubscriptionIdentifiersAvailable, false);
        }

-        public void WriteSharedSubscriptionAvailable(bool? value)
+        public void WriteSharedSubscriptionAvailable(bool value)
        {
-            Write(MqttPropertyId.SharedSubscriptionAvailable, value);
+            if (value)
+            {
+                // Absence of the flag means it is supported! 
+                return;
+            }
+            
+            Write(MqttPropertyId.SharedSubscriptionAvailable, false);
        }

        public void WriteServerKeepAlive(ushort? value)
@@ -221,15 +239,10 @@ namespace MQTTnet.Formatter.V5
            _packetWriter.Write(value.Value);
        }

-        void WriteAsVariableLengthInteger(MqttPropertyId id, uint? value)
+        void WriteAsVariableLengthInteger(MqttPropertyId id, uint value)
        {
-            if (!value.HasValue)
-            {
-                return;
-            }
-
            _packetWriter.Write((byte)id);
-            _packetWriter.WriteVariableLengthInteger(value.Value);
+            _packetWriter.WriteVariableLengthInteger(value);
        }

        void WriteAsFourByteInteger(MqttPropertyId id, uint? value)