UdpDiscoveryMessageFilter.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / System.ServiceModel.Discovery / System / ServiceModel / Discovery / UdpDiscoveryMessageFilter.cs / 1305376 / UdpDiscoveryMessageFilter.cs
                        

                        
                            //---------------------------------------------------------------- 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//---------------------------------------------------------------
namespace System.ServiceModel.Discovery
{ 
    using System.ServiceModel.Channels;
    using System.ServiceModel.Dispatcher; 
 
    // This class provides a mitigration to the DDOS threat when using Discovery APIs with
    // UDP multicast transport. 
    //
    // The Probe and Resolve request are sent multicast and are not secure. An attacker can launch
    // a third party distributed DOS attack by setting the address of the third party in the ReplyTo
    // header of the Probe and Resolve requests. To mitigate this threat this behavior drops the 
    // message that have ReplyTo set to a value that is not annonymous by setting appropriate
    // message filter. 
    // 
    class UdpDiscoveryMessageFilter : MessageFilter
    { 
        MessageFilter innerFilter;

        public UdpDiscoveryMessageFilter(MessageFilter innerFilter)
        { 
            if (innerFilter == null)
            { 
                throw FxTrace.Exception.ArgumentNull("innerFilter"); 
            }
 
            this.innerFilter = innerFilter;
        }

        public MessageFilter InnerFilter 
        {
            get 
            { 
                return this.innerFilter;
            } 
        }

        public override bool Match(Message message)
        { 
            if (message == null)
            { 
                throw FxTrace.Exception.ArgumentNull("message"); 
            }
 
            if (InnerFilter.Match(message))
            {
                bool isMatch = ((message.Headers.ReplyTo == null) ||
                    (message.Headers.ReplyTo.IsAnonymous)); 

                if (!isMatch && TD.DiscoveryMessageWithInvalidReplyToIsEnabled()) 
                { 
                    TD.DiscoveryMessageWithInvalidReplyTo(message.Headers.MessageId.ToString());
                } 

                return isMatch;
            }
 
            return false;
        } 
 
        public override bool Match(MessageBuffer buffer)
        { 
            if (buffer == null)
            {
                throw FxTrace.Exception.ArgumentNull("buffer");
            } 

            return this.Match(buffer.CreateMessage()); 
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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