private void UpdateServerDomain(string serverDomain)
{
_soaRecord = new DnsSOARecordData(serverDomain, "hostadmin@" + serverDomain, 1, 900, 300, 604800, 60);
_nsRecord = new DnsNSRecordData(serverDomain);
_zoneManager.ServerDomain = serverDomain;
}
public static async Task <StubZone> CreateAsync(DnsServer dnsServer, string name, string primaryNameServerAddresses = null)
{
StubZone stubZone = new StubZone(dnsServer, name);
DnsQuestionRecord soaQuestion = new DnsQuestionRecord(name, DnsResourceRecordType.SOA, DnsClass.IN);
DnsDatagram soaResponse;
if (primaryNameServerAddresses == null)
{
soaResponse = await stubZone._dnsServer.DirectQueryAsync(soaQuestion);
}
else
{
DnsClient dnsClient = new DnsClient(primaryNameServerAddresses);
foreach (NameServerAddress nameServerAddress in dnsClient.Servers)
{
if (nameServerAddress.IsIPEndPointStale)
{
await nameServerAddress.ResolveIPAddressAsync(stubZone._dnsServer, stubZone._dnsServer.PreferIPv6);
}
}
dnsClient.Proxy = stubZone._dnsServer.Proxy;
dnsClient.PreferIPv6 = stubZone._dnsServer.PreferIPv6;
DnsDatagram soaRequest = new DnsDatagram(0, false, DnsOpcode.StandardQuery, false, false, false, false, false, false, DnsResponseCode.NoError, new DnsQuestionRecord[] { soaQuestion }, null, null, null, DnsDatagram.EDNS_DEFAULT_UDP_PAYLOAD_SIZE);
soaResponse = await dnsClient.ResolveAsync(soaRequest);
}
if ((soaResponse.Answer.Count == 0) || (soaResponse.Answer[0].Type != DnsResourceRecordType.SOA))
{
throw new DnsServerException("DNS Server failed to find SOA record for: " + name);
}
DnsSOARecordData receivedSoa = soaResponse.Answer[0].RDATA as DnsSOARecordData;
DnsSOARecordData soa = new DnsSOARecordData(receivedSoa.PrimaryNameServer, receivedSoa.ResponsiblePerson, 0u, receivedSoa.Refresh, receivedSoa.Retry, receivedSoa.Expire, receivedSoa.Minimum);
DnsResourceRecord[] soaRR = new DnsResourceRecord[] { new DnsResourceRecord(stubZone._name, DnsResourceRecordType.SOA, DnsClass.IN, soa.Refresh, soa) };
if (!string.IsNullOrEmpty(primaryNameServerAddresses))
{
soaRR[0].SetPrimaryNameServers(primaryNameServerAddresses);
}
stubZone._entries[DnsResourceRecordType.SOA] = soaRR;
stubZone._isExpired = true; //new stub zone is considered expired till it refreshes
stubZone._refreshTimer = new Timer(stubZone.RefreshTimerCallback, null, Timeout.Infinite, Timeout.Infinite);
return(stubZone);
}
public Task InitializeAsync(IDnsServer dnsServer, string config)
{
_soaRecord = new DnsSOARecordData(dnsServer.ServerDomain, "hostadmin@" + dnsServer.ServerDomain, 1, 14400, 3600, 604800, 60);
dynamic jsonConfig = JsonConvert.DeserializeObject(config);
_enableBlocking = jsonConfig.enableBlocking.Value;
_allowTxtBlockingReport = jsonConfig.allowTxtBlockingReport.Value;
_blockListZone = ReadJsonDomainArray(jsonConfig.blocked);
return(Task.CompletedTask);
}
protected void CleanupHistory(List <DnsResourceRecord> history)
{
DnsSOARecordData soa = _entries[DnsResourceRecordType.SOA][0].RDATA as DnsSOARecordData;
DateTime expiry = DateTime.UtcNow.AddSeconds(-soa.Expire);
int index = 0;
while (index < history.Count)
{
//check difference sequence
if (history[index].GetDeletedOn() > expiry)
{
break; //found record to keep
}
//skip to next difference sequence
index++;
int soaCount = 1;
while (index < history.Count)
{
if (history[index].Type == DnsResourceRecordType.SOA)
{
soaCount++;
if (soaCount == 3)
{
break;
}
}
index++;
}
}
if (index == history.Count)
{
//delete entire history
history.Clear();
return;
}
//remove expired records
history.RemoveRange(0, index);
}
private async Task <bool> RefreshZoneAsync(IReadOnlyList <NameServerAddress> nameServers)
{
try
{
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server has started zone refresh for stub zone: " + (_name == "" ? "<root>" : _name));
}
}
DnsClient client = new DnsClient(nameServers);
client.Proxy = _dnsServer.Proxy;
client.PreferIPv6 = _dnsServer.PreferIPv6;
client.Timeout = REFRESH_TIMEOUT;
client.Retries = REFRESH_RETRIES;
client.Concurrency = 1;
DnsDatagram soaRequest = new DnsDatagram(0, false, DnsOpcode.StandardQuery, false, false, false, false, false, false, DnsResponseCode.NoError, new DnsQuestionRecord[] { new DnsQuestionRecord(_name, DnsResourceRecordType.SOA, DnsClass.IN) }, null, null, null, DnsDatagram.EDNS_DEFAULT_UDP_PAYLOAD_SIZE);
DnsDatagram soaResponse = await client.ResolveAsync(soaRequest);
if (soaResponse.RCODE != DnsResponseCode.NoError)
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server received RCODE=" + soaResponse.RCODE.ToString() + " for '" + (_name == "" ? "<root>" : _name) + "' stub zone refresh from: " + soaResponse.Metadata.NameServerAddress.ToString());
}
return(false);
}
if ((soaResponse.Answer.Count < 1) || (soaResponse.Answer[0].Type != DnsResourceRecordType.SOA) || !_name.Equals(soaResponse.Answer[0].Name, StringComparison.OrdinalIgnoreCase))
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server received an empty response for SOA query for '" + (_name == "" ? "<root>" : _name) + "' stub zone refresh from: " + soaResponse.Metadata.NameServerAddress.ToString());
}
return(false);
}
DnsResourceRecord currentSoaRecord = _entries[DnsResourceRecordType.SOA][0];
DnsResourceRecord receivedSoaRecord = soaResponse.Answer[0];
DnsSOARecordData currentSoa = currentSoaRecord.RDATA as DnsSOARecordData;
DnsSOARecordData receivedSoa = receivedSoaRecord.RDATA as DnsSOARecordData;
//compare using sequence space arithmetic
if (!_resync && !currentSoa.IsZoneUpdateAvailable(receivedSoa))
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server successfully checked for '" + (_name == "" ? "<root>" : _name) + "' stub zone update from: " + soaResponse.Metadata.NameServerAddress.ToString());
}
return(true);
}
//update available; do zone sync with TCP transport
List <NameServerAddress> tcpNameServers = new List <NameServerAddress>();
foreach (NameServerAddress nameServer in nameServers)
{
tcpNameServers.Add(nameServer.ChangeProtocol(DnsTransportProtocol.Tcp));
}
nameServers = tcpNameServers;
client = new DnsClient(nameServers);
client.Proxy = _dnsServer.Proxy;
client.PreferIPv6 = _dnsServer.PreferIPv6;
client.Timeout = REFRESH_TIMEOUT;
client.Retries = REFRESH_RETRIES;
client.Concurrency = 1;
DnsDatagram nsRequest = new DnsDatagram(0, false, DnsOpcode.StandardQuery, false, false, false, false, false, false, DnsResponseCode.NoError, new DnsQuestionRecord[] { new DnsQuestionRecord(_name, DnsResourceRecordType.NS, DnsClass.IN) });
DnsDatagram nsResponse = await client.ResolveAsync(nsRequest);
if (nsResponse.RCODE != DnsResponseCode.NoError)
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server received RCODE=" + nsResponse.RCODE.ToString() + " for '" + (_name == "" ? "<root>" : _name) + "' stub zone refresh from: " + nsResponse.Metadata.NameServerAddress.ToString());
}
return(false);
}
if (nsResponse.Answer.Count < 1)
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server received an empty response for NS query for '" + (_name == "" ? "<root>" : _name) + "' stub zone from: " + nsResponse.Metadata.NameServerAddress.ToString());
}
return(false);
}
//prepare sync records
List <DnsResourceRecord> nsRecords = new List <DnsResourceRecord>(nsResponse.Answer.Count);
foreach (DnsResourceRecord record in nsResponse.Answer)
{
if ((record.Type == DnsResourceRecordType.NS) && record.Name.Equals(_name, StringComparison.OrdinalIgnoreCase))
{
record.SyncGlueRecords(nsResponse.Additional);
nsRecords.Add(record);
}
}
receivedSoaRecord.CopyRecordInfoFrom(currentSoaRecord);
//sync records
_entries[DnsResourceRecordType.NS] = nsRecords;
_entries[DnsResourceRecordType.SOA] = new DnsResourceRecord[] { receivedSoaRecord };
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server successfully refreshed '" + (_name == "" ? "<root>" : _name) + "' stub zone from: " + nsResponse.Metadata.NameServerAddress.ToString());
}
}
return(true);
}
catch (Exception ex)
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
string strNameServers = null;
foreach (NameServerAddress nameServer in nameServers)
{
if (strNameServers == null)
{
strNameServers = nameServer.ToString();
}
else
{
strNameServers += ", " + nameServer.ToString();
}
}
log.Write("DNS Server failed to refresh '" + (_name == "" ? "<root>" : _name) + "' stub zone from: " + strNameServers);
log.Write(ex);
}
return(false);
}
}
private async void RefreshTimerCallback(object state)
{
try
{
if (_disabled && !_resync)
{
return;
}
_isExpired = DateTime.UtcNow > _expiry;
//get primary name server addresses
IReadOnlyList <NameServerAddress> primaryNameServers = await GetPrimaryNameServerAddressesAsync(_dnsServer);
if (primaryNameServers.Count == 0)
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write("DNS Server could not find primary name server IP addresses for stub zone: " + (_name == "" ? "<root>" : _name));
}
//set timer for retry
DnsSOARecordData soa1 = _entries[DnsResourceRecordType.SOA][0].RDATA as DnsSOARecordData;
ResetRefreshTimer(soa1.Retry * 1000);
_syncFailed = true;
return;
}
//refresh zone
if (await RefreshZoneAsync(primaryNameServers))
{
//zone refreshed; set timer for refresh
DnsSOARecordData latestSoa = _entries[DnsResourceRecordType.SOA][0].RDATA as DnsSOARecordData;
ResetRefreshTimer(latestSoa.Refresh * 1000);
_syncFailed = false;
_expiry = DateTime.UtcNow.AddSeconds(latestSoa.Expire);
_isExpired = false;
_resync = false;
_dnsServer.AuthZoneManager.SaveZoneFile(_name);
return;
}
//no response from any of the name servers; set timer for retry
DnsSOARecordData soa = _entries[DnsResourceRecordType.SOA][0].RDATA as DnsSOARecordData;
ResetRefreshTimer(soa.Retry * 1000);
_syncFailed = true;
}
catch (Exception ex)
{
LogManager log = _dnsServer.LogManager;
if (log != null)
{
log.Write(ex);
}
//set timer for retry
DnsSOARecordData soa = _entries[DnsResourceRecordType.SOA][0].RDATA as DnsSOARecordData;
ResetRefreshTimer(soa.Retry * 1000);
_syncFailed = true;
}
finally
{
_refreshTimerTriggered = false;
}
}
private void UpdateServerDomain(string serverDomain)
{
_soaRecord = new DnsSOARecordData(serverDomain, "hostadmin@" + serverDomain, 1, 14400, 3600, 604800, 60);
_nsRecord = new DnsNSRecordData(serverDomain);
}
