public void CleanupCache()
{
// remove everythign older than 15 minutes
DateTime AgeLimit = DateTime.Now.AddMinutes(-15);
foreach (IPAddress remoteAddress in ReverseDnsCache.Keys.ToList())
{
ReverseDnsEntry value = ReverseDnsCache[remoteAddress];
if (value.TimeStamp < AgeLimit)
{
ReverseDnsCache.Remove(remoteAddress);
}
}
}
public bool LookupHostName(IPAddress remoteAddress, object target, Action <object, string, NameSources> setter)
{
if (remoteAddress.Equals(IPAddress.Any) || remoteAddress.Equals(IPAddress.IPv6Any))
{
return(true);
}
if (remoteAddress.Equals(IPAddress.Loopback) || remoteAddress.Equals(IPAddress.IPv6Loopback))
{
return(true);
}
ReverseDnsEntry Entry = null;
if (ReverseDnsCache.TryGetValue(remoteAddress, out Entry))
{
if ((Entry.TimeStamp + (5 * 60 * 1000) >= MiscFunc.GetCurTick()))
{
if (Entry.HostName != null)
{
setter(target, Entry.HostName, NameSources.ReverseDNS);
}
return(true);
}
}
if (Entry == null)
{
Entry = new ReverseDnsEntry();
ReverseDnsCache.Add(remoteAddress, Entry);
}
if (Entry.PendingJobs == null)
{
Entry.PendingJobs = new List <HostLookupJob>();
//AppLog.Debug("reverse looking up : {0}", remoteAddress.ToString());
// todo: use matibe api to save oin dns queries
Dns.BeginGetHostEntry(remoteAddress, (x) =>
{
// WARNING: this function is called from the worker thread
//x.AsyncState
IPHostEntry hostInfo = null;
try
{
hostInfo = Dns.EndGetHostEntry(x);
}
catch { }
App.engine?.RunInEngineThread(() =>
{
// Note: this happens in the engine thread
Entry.TimeStamp = MiscFunc.GetCurTick();
if (hostInfo != null)
{
Entry.HostName = hostInfo.HostName;
}
if (Entry.HostName != null)
{
foreach (var job in Entry.PendingJobs)
{
job.SetHostName(Entry.HostName, NameSources.ReverseDNS);
}
}
Entry.PendingJobs = null;
});
}, null);
}
Entry.PendingJobs.Add(new HostLookupJob()
{
target = new WeakReference(target), setter = setter
});
return(false);
}
public List <HostNameEntry> ResolveHostNames(IPAddress remoteAddress)
{
if (remoteAddress.Equals(IPAddress.Any) || remoteAddress.Equals(IPAddress.IPv6Any))
{
return(new List <HostNameEntry>());
}
if (remoteAddress.Equals(IPAddress.Loopback) || remoteAddress.Equals(IPAddress.IPv6Loopback))
{
return new List <HostNameEntry>()
{
new HostNameEntry()
{
HostName = "localhost", TimeStamp = DateTime.Now
}
}
}
;
ReverseDnsEntry Entry = null;
if (ReverseDnsCache.TryGetValue(remoteAddress, out Entry))
{
if (Entry.HostNames.Count > 0)
{
List <HostNameEntry> List = new List <HostNameEntry>();
foreach (string HostName in Entry.HostNames)
{
List.Add(new HostNameEntry()
{
HostName = HostName, TimeStamp = Entry.TimeStamp
});
}
return(List);
}
else if (Entry.Pending)
{
return(null);
}
else if ((Entry.TimeStamp.AddMinutes(1) > DateTime.Now))
{
return(new List <HostNameEntry>()); // dont re query if teh last query failed
}
}
if (Entry == null)
{
Entry = new ReverseDnsEntry();
Entry.Pending = true;
ReverseDnsCache.Add(remoteAddress, Entry);
}
AppLog.Debug("reverse looking up : {0}", remoteAddress.ToString());
Thread task = new Thread(() => {
// WARNING: this function is called from the worker thread
string AddressReverse = Address2RevDnsHost(remoteAddress);
List <string> HostNames = new List <string>();
try
{
var resultPtr = IntPtr.Zero;
if (DnsApi.DnsQuery(AddressReverse, DnsApi.DnsRecordType.PTR, DnsApi.DnsQueryType.DNS_QUERY_NO_HOSTS_FILE, IntPtr.Zero, ref resultPtr, IntPtr.Zero) == DnsApi.ERROR_SUCCESS)
{
for (var recordIndexPtr = resultPtr; recordIndexPtr != IntPtr.Zero;)
{
var record = (DnsApi.DnsRecord)Marshal.PtrToStructure(recordIndexPtr, typeof(DnsApi.DnsRecord));
int offset = Marshal.OffsetOf(typeof(DnsApi.DnsRecord), "Data").ToInt32();
IntPtr data = recordIndexPtr + offset;
recordIndexPtr = record.Next;
if (record.Type != DnsApi.DnsRecordType.PTR)
{
continue;
}
var ptr = (DnsApi.DnsPTRRecord)Marshal.PtrToStructure(data, typeof(DnsApi.DnsPTRRecord));
HostNames.Add(ptr.NameHost);
}
if (resultPtr != IntPtr.Zero)
{
DnsApi.DnsRecordListFree(resultPtr, DnsApi.DnsFreeType.DnsFreeRecordList);
}
}
}
catch (Exception err)
{
AppLog.Exception(err);
}
App.engine?.RunInEngineThread(() =>
{
// Note: this happens in the engine thread
Entry.TimeStamp = DateTime.Now;
Entry.HostNames = HostNames;
Entry.Pending = false;
HostNameResolved?.Invoke(this, new DnsEvent()
{
RemoteAddress = remoteAddress, HostNames = HostNames /*, TimeStamp = Entry.TimeStamp*/
});
});
});
task.Start();
return(null);
}
