Files
DnsServer/DnsServerCore/Dns/ResolverPrefetchDnsCache.cs

63 lines
2.0 KiB
C#

/*
Technitium DNS Server
Copyright (C) 2024 Shreyas Zare (shreyas@technitium.com)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
using TechnitiumLibrary.Net.Dns;
namespace DnsServerCore.Dns
{
class ResolverPrefetchDnsCache : ResolverDnsCache
{
#region variables
readonly DnsQuestionRecord _prefetchQuestion;
#endregion
#region constructor
public ResolverPrefetchDnsCache(DnsServer dnsServer, bool skipDnsAppAuthoritativeRequestHandlers, DnsQuestionRecord prefetchQuestion)
: base(dnsServer, skipDnsAppAuthoritativeRequestHandlers)
{
_prefetchQuestion = prefetchQuestion;
}
#endregion
#region public
public override DnsDatagram Query(DnsDatagram request, bool serveStale = false, bool findClosestNameServers = false, bool resetExpiry = false)
{
if (_prefetchQuestion.Equals(request.Question[0]))
{
//request is for prefetch question
if (!findClosestNameServers)
return null; //dont give answer from cache for prefetch question
//return closest name servers so that the recursive resolver queries them to refreshes cache instead of returning response from cache
return QueryClosestDelegation(request);
}
return base.Query(request, serveStale, findClosestNameServers, resetExpiry);
}
#endregion
}
}