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Fix client session takeover

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This commit is contained in:
Christian
2022-11-06 13:28:41 +01:00
parent 97c46bea0f
commit 5c74728387
21 changed files with 588 additions and 558 deletions
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Source/MQTTnet/Server/Internal/MqttClientSubscriptionsManager.cs
+25 -41
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@@ -7,6 +7,7 @@ using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using MQTTnet.Internal;
using MQTTnet.Packets;
using MQTTnet.Protocol;
@@ -30,7 +31,7 @@ namespace MQTTnet.Server
readonly Dictionary<string, MqttSubscription> _subscriptions = new Dictionary<string, MqttSubscription>();
// Use subscription lock to maintain consistency across subscriptions and topic hash dictionaries
readonly SemaphoreSlim _subscriptionsLock = new SemaphoreSlim(1);
readonly AsyncLock _subscriptionsLock = new AsyncLock();
readonly Dictionary<ulong, TopicHashMaskSubscriptions> _wildcardSubscriptionsByTopicHash = new Dictionary<ulong, TopicHashMaskSubscriptions>();
public MqttClientSubscriptionsManager(
@@ -45,13 +46,12 @@ namespace MQTTnet.Server
_subscriptionChangedNotification = subscriptionChangedNotification;
}
public CheckSubscriptionsResult CheckSubscriptions(string topic, ulong topicHash, MqttQualityOfServiceLevel applicationMessageQoSLevel, string senderClientId)
public CheckSubscriptionsResult CheckSubscriptions(string topic, ulong topicHash, MqttQualityOfServiceLevel qualityOfServiceLevel, string senderId)
{
var possibleSubscriptions = new List<MqttSubscription>();
// Check for possible subscriptions. They might have collisions but this is fine.
_subscriptionsLock.Wait();
try
using (_subscriptionsLock.EnterAsync(CancellationToken.None).GetAwaiter().GetResult())
{
if (_noWildcardSubscriptionsByTopicHash.TryGetValue(topicHash, out var noWildcardSubscriptions))
{
@@ -63,18 +63,14 @@ namespace MQTTnet.Server
var wildcardSubscriptions = wcs.Value;
var subscriptionHash = wcs.Key;
var subscriptionHashMask = wildcardSubscriptions.HashMask;
if ((topicHash & subscriptionHashMask) == subscriptionHash)
{
possibleSubscriptions.AddRange(wildcardSubscriptions.Subscriptions.ToList());
}
}
}
finally
{
_subscriptionsLock.Release();
}
// The pre check has evaluated that nothing is subscribed.
// If there were some possible candidates they get checked below
// again to avoid collisions.
@@ -83,7 +79,7 @@ namespace MQTTnet.Server
return CheckSubscriptionsResult.NotSubscribed;
}
var senderIsReceiver = string.Equals(senderClientId, _session.Id);
var senderIsReceiver = string.Equals(senderId, _session.Id);
var maxQoSLevel = -1; // Not subscribed.
HashSet<uint> subscriptionIdentifiers = null;
@@ -136,7 +132,7 @@ namespace MQTTnet.Server
SubscriptionIdentifiers = subscriptionIdentifiers?.ToList() ?? EmptySubscriptionIdentifiers,
// Start with the same QoS as the publisher.
QualityOfServiceLevel = applicationMessageQoSLevel
QualityOfServiceLevel = qualityOfServiceLevel
};
// Now downgrade if required.
@@ -148,7 +144,7 @@ namespace MQTTnet.Server
// Subscribing to a Topic Filter at QoS 2 is equivalent to saying "I would like to receive Messages matching this filter at the QoS with which they were published".
// This means a publisher is responsible for determining the maximum QoS a Message can be delivered at, but a subscriber is able to require that the Server
// downgrades the QoS to one more suitable for its usage.
if (maxQoSLevel < (int)applicationMessageQoSLevel)
if (maxQoSLevel < (int)qualityOfServiceLevel)
{
result.QualityOfServiceLevel = (MqttQualityOfServiceLevel)maxQoSLevel;
}
@@ -209,7 +205,7 @@ namespace MQTTnet.Server
// This call will add the new subscription to the internal storage.
// So the event _ClientSubscribedTopicEvent_ must be called afterwards.
_subscriptionChangedNotification?.OnSubscriptionsAdded(_session, addedSubscriptions);
if (_eventContainer.ClientSubscribedTopicEvent.HasHandlers)
{
foreach (var finalTopicFilter in finalTopicFilters)
@@ -218,23 +214,22 @@ namespace MQTTnet.Server
await _eventContainer.ClientSubscribedTopicEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
}
}
return result;
}
public async Task<MqttUnsubscribeResult> Unsubscribe(MqttUnsubscribePacket unsubscribePacket, CancellationToken cancellationToken)
public async Task<UnsubscribeResult> Unsubscribe(MqttUnsubscribePacket unsubscribePacket, CancellationToken cancellationToken)
{
if (unsubscribePacket == null)
{
throw new ArgumentNullException(nameof(unsubscribePacket));
}
var result = new MqttUnsubscribeResult();
var result = new UnsubscribeResult();
var removedSubscriptions = new List<string>();
await _subscriptionsLock.WaitAsync(cancellationToken).ConfigureAwait(false);
try
using (await _subscriptionsLock.EnterAsync(cancellationToken).ConfigureAwait(false))
{
foreach (var topicFilter in unsubscribePacket.TopicFilters)
{
@@ -265,7 +260,7 @@ namespace MQTTnet.Server
if (existingSubscription != null)
{
var topicHash = existingSubscription.TopicHash;
if (existingSubscription.TopicHasWildcard)
{
if (_wildcardSubscriptionsByTopicHash.TryGetValue(topicHash, out var subscriptions))
@@ -294,11 +289,8 @@ namespace MQTTnet.Server
}
}
}
finally
{
_subscriptionsLock.Release();
_subscriptionChangedNotification?.OnSubscriptionsRemoved(_session, removedSubscriptions);
}
_subscriptionChangedNotification?.OnSubscriptionsRemoved(_session, removedSubscriptions);
if (_eventContainer.ClientUnsubscribedTopicEvent.HasHandlers)
{
@@ -345,8 +337,7 @@ namespace MQTTnet.Server
// Add to subscriptions and maintain topic hash dictionaries
_subscriptionsLock.Wait();
try
using (_subscriptionsLock.EnterAsync(CancellationToken.None).GetAwaiter().GetResult())
{
MqttSubscription.CalculateTopicHash(topicFilter.Topic, out var topicHash, out var topicHashMask, out var hasWildcard);
@@ -396,10 +387,6 @@ namespace MQTTnet.Server
subscriptions.Add(subscription);
}
}
finally
{
_subscriptionsLock.Release();
}
return new CreateSubscriptionResult
{
@@ -493,23 +480,20 @@ namespace MQTTnet.Server
async Task<InterceptingUnsubscriptionEventArgs> InterceptUnsubscribe(string topicFilter, MqttSubscription mqttSubscription, CancellationToken cancellationToken)
{
var clientUnsubscribingTopicEventArgs = new InterceptingUnsubscriptionEventArgs(cancellationToken, topicFilter, _session.Items, topicFilter);
if (mqttSubscription == null)
var clientUnsubscribingTopicEventArgs = new InterceptingUnsubscriptionEventArgs(cancellationToken, topicFilter, _session.Items, topicFilter)
{
clientUnsubscribingTopicEventArgs.Response.ReasonCode = MqttUnsubscribeReasonCode.NoSubscriptionExisted;
}
else
{
clientUnsubscribingTopicEventArgs.Response.ReasonCode = MqttUnsubscribeReasonCode.Success;
}
Response =
{
ReasonCode = mqttSubscription == null ? MqttUnsubscribeReasonCode.NoSubscriptionExisted : MqttUnsubscribeReasonCode.Success
}
};
await _eventContainer.InterceptingUnsubscriptionEvent.InvokeAsync(clientUnsubscribingTopicEventArgs).ConfigureAwait(false);
return clientUnsubscribingTopicEventArgs;
}
public sealed class CreateSubscriptionResult
sealed class CreateSubscriptionResult
{
public bool IsNewSubscription { get; set; }