ConnectionsExceeded.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Xml;
using Waher.Content;
using Waher.Networking.HTTP.Interfaces;
using Waher.Runtime.IO;
using Waher.Runtime.Threading;
 
namespace Waher.Security.WAF.Model.Comparisons
{
    public class ConnectionsExceeded : RateLimitComparison
    {
        public ConnectionsExceeded()
            : base()
        {
        }
 
        public ConnectionsExceeded(XmlElement Xml, WafAction Parent, WebApplicationFirewall Document)
            : base(Xml, Parent, Document)
        {
        }
 
        public override string LocalName => nameof(ConnectionsExceeded);
 
        public override WafAction Create(XmlElement Xml, WafAction Parent, WebApplicationFirewall Document) => new ConnectionsExceeded(Xml, Parent, Document);
 
        public override async Task<WafResult?> Review(ProcessingState State)
        {
            string Endpoint = State.Request.RemoteEndPoint;
            string Key = Endpoint.RemovePortNumber() + "|Connections";
            long Count;
 
            using (Semaphore Semaphore = await Semaphores.BeginWrite(Key))
            {
                if (State.TryGetCachedObject(Key, out Dictionary<string, bool> Connections))
                    Connections[Endpoint] = true;
                else
                {
                    Duration Duration = await this.EvaluateDurationAsync(State);
 
                    Connections = new Dictionary<string, bool>()
                    {
                        { Endpoint, true }
                    };
 
                    State.AddToCache(Key, Connections, DateTime.UtcNow + Duration);
                }
 
                Count = Connections.Count;
            }
 
            return await this.Review(State, Count);
        }
    }
}