public HttpRequestRateLimiterMiddleware(RequestDelegate next, IOptions <HttpRequestRateLimiterOptions <TKey> > options, IConfiguration config, ILoggerFactory loggerFactory)
{
Next = next ?? throw new ArgumentNullException(nameof(next));
Config = config ?? throw new ArgumentNullException(nameof(config));
Options = options?.Value ?? throw new ArgumentNullException(nameof(options));
RateLimiter = new RateLimiter <TKey>(RateLimiterOptions);
ConcurrentLimiter = new ConcurrentLimiter <TKey>(Options.MaxConcurrentRequestsPerSrcSubnet);
}
// Factory メソッド
public static IHttpRequestRateLimiterHashKey?CreateFromHttpContext <TKey>(HttpContext context, HttpRequestRateLimiterOptions <TKey> options) where TKey : IHttpRequestRateLimiterHashKey
{
// Src IP の処理
IPAddress srcIp = context.Connection.RemoteIpAddress._UnmapIPv4();
if (options.SrcIPExcludeLocalNetwork)
{
// ローカルネットワークを除外する
if (srcIp._GetIPAddressType()._IsLocalNetwork())
{
return(null);
}
}
// サブネットマスクの AND をする
if (srcIp.AddressFamily == AddressFamily.InterNetwork)
{
// IPv4
srcIp = IPUtil.IPAnd(srcIp, IPUtil.IntToSubnetMask4(options.SrcIPv4SubnetLength));
}
else
{
// IPv6
srcIp = IPUtil.IPAnd(srcIp, IPUtil.IntToSubnetMask6(options.SrcIPv6SubnetLength));
}
if (typeof(TKey) == typeof(SrcIPAddress))
{
if (srcIp != null)
{
return(new SrcIPAddress(srcIp));
}
}
return(null);
}