private static void QueueLookup(LookupRequest lookupRequest)
{
LookupRequest inProgressLookup = (from lookup in m_inProgressLookups where lookup.Key == lookupRequest.id() select lookup.Value).FirstOrDefault();
if (inProgressLookup == null)
{
m_inProgressLookups.TryAdd(lookupRequest.id(), lookupRequest);
m_queuedLookups.Enqueue(lookupRequest);
logger.LogDebug("DNSManager lookup queued for " + lookupRequest.QueryType + " " + lookupRequest.Hostname + ", queue size=" + m_queuedLookups.Count + ", in progress=" + m_queuedLookups.Count + ".");
m_lookupARE.Set();
}
else
{
if (lookupRequest.CompleteEvent != null)
{
if (inProgressLookup.Duplicates == null)
{
inProgressLookup.Duplicates = new List <LookupRequest>()
{
lookupRequest
};
}
else
{
inProgressLookup.Duplicates.Add(lookupRequest);
}
logger.LogDebug("DNSManager duplicate lookup added for " + lookupRequest.QueryType + " " + lookupRequest.Hostname + ", queue size=" + m_queuedLookups.Count + ", in progress=" + m_queuedLookups.Count + ".");
}
}
}
private static void ProcessLookups()
{
string hostname = null;
try
{
string threadName = Thread.CurrentThread.Name;
//logger.LogDebug("DNS Lookup Thread " + threadName + " started.");
while (!m_close)
{
int lookups = 0;
while (m_queuedLookups.Count > 0 && !m_close)
{
LookupRequest lookupRequest = LookupRequest.Empty;
string queryType = null;
//string hostname = null;
DNSResponse dnsResponse = null;
DateTime startLookupTime = DateTime.Now;
try
{
if (m_queuedLookups.Count > 0)
{
if (m_queuedLookups.TryDequeue(out lookupRequest))
{
hostname = lookupRequest.Hostname;
queryType = lookupRequest.QueryType.ToString();
}
}
else
{
// Another thread got in ahead of this one to do the lookup.
continue;
}
lookups++;
logger.LogDebug("DNSManager thread " + threadName + " looking up " + queryType + " " + lookupRequest.Hostname + ".");
if (lookupRequest.DNSServers == null)
{
dnsResponse = m_resolver.Query(lookupRequest.Hostname, lookupRequest.QueryType, lookupRequest.Timeout);
}
else
{
dnsResponse = m_resolver.Query(lookupRequest.Hostname, lookupRequest.QueryType, lookupRequest.Timeout, lookupRequest.DNSServers);
}
bool bDnsErr = false;
if (dnsResponse == null)
{
logger.LogWarning("DNSManager resolution error for " + lookupRequest.QueryType + " " + lookupRequest.Hostname + " no response was returned. Time taken=" + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds + "ms.");
bDnsErr = true;
}
else if (!string.IsNullOrWhiteSpace(dnsResponse.Error))
{
logger.LogWarning("DNSManager resolution error for " + lookupRequest.QueryType + " " + lookupRequest.Hostname + ". " + dnsResponse.Error + ". Time taken=" + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds + "ms.");
bDnsErr = true;
}
//rj2: use default dns suffixes for address resolution
for (int iSuffix = 0; iSuffix < DNSManager.GetDnsSuffixes().Length&& bDnsErr && DNSManager.UseDNSSuffixes && !m_close; iSuffix++)
{
string host = lookupRequest.Hostname;
if (!host.EndsWith("."))
{
host += ".";
}
host += DNSManager.m_dnsSuffixes[iSuffix];
if (lookupRequest.DNSServers == null)
{
dnsResponse = m_resolver.Query(host, lookupRequest.QueryType, lookupRequest.Timeout);
}
else
{
dnsResponse = m_resolver.Query(host, lookupRequest.QueryType, lookupRequest.Timeout, lookupRequest.DNSServers);
}
bDnsErr = false;
if (dnsResponse == null)
{
logger.LogWarning("DNSManager resolution error for " + lookupRequest.QueryType + " " + host + " no response was returned. Time taken=" + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds + "ms.");
bDnsErr = true;
}
else if (!string.IsNullOrWhiteSpace(dnsResponse.Error))
{
logger.LogWarning("DNSManager resolution error for " + lookupRequest.QueryType + " " + host + ". " + dnsResponse.Error + ". Time taken=" + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds + "ms.");
bDnsErr = true;
}
}
if (bDnsErr)
{
}
else if (lookupRequest.QueryType == QType.A)
{
if (dnsResponse?.RecordsA.Length > 0)
{
logger.LogDebug($"DNSManager resolved A record for {lookupRequest.Hostname} to {dnsResponse.RecordsA[0].Address.ToString()} with TTL {dnsResponse.RecordsA[0].RR.TTL} in {DateTime.Now.Subtract(startLookupTime).TotalMilliseconds.ToString("0.##")}ms.");
}
else
{
logger.LogWarning("DNSManager could not resolve A record for " + lookupRequest.Hostname + " in " + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds.ToString("0.##") + "ms.");
}
}
else if (lookupRequest.QueryType == QType.AAAA)
{
if (dnsResponse?.RecordsAAAA.Length > 0)
{
logger.LogDebug($"DNSManager resolved AAAA record for {lookupRequest.Hostname} to {dnsResponse.RecordsAAAA[0].Address.ToString()} with TTL {dnsResponse.RecordsAAAA[0].RR.TTL} in {DateTime.Now.Subtract(startLookupTime).TotalMilliseconds.ToString("0.##")}ms.");
}
else
{
logger.LogWarning("DNSManager could not resolve AAAA record for " + lookupRequest.Hostname + " in " + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds.ToString("0.##") + "ms.");
}
}
else if (lookupRequest.QueryType == QType.SRV)
{
logger.LogDebug("DNSManager resolve time for " + lookupRequest.Hostname + " " + lookupRequest.QueryType + " " + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds.ToString("0.##") + "ms.");
if (dnsResponse.RecordsRR == null || dnsResponse.RecordsRR.Length == 0)
{
logger.LogDebug(" no SRV resource records found for " + lookupRequest.Hostname + ".");
}
else
{
foreach (RecordSRV srvRecord in dnsResponse.RecordSRV)
{
logger.LogDebug(" result: priority=" + srvRecord.PRIORITY + ", weight=" + srvRecord.WEIGHT + ", port=" + srvRecord.PORT + ", target=" + srvRecord.TARGET + ".");
}
}
}
else
{
logger.LogDebug("DNSManager resolve time for " + lookupRequest.Hostname + " " + lookupRequest.QueryType + " " + DateTime.Now.Subtract(startLookupTime).TotalMilliseconds.ToString("0.##") + "ms.");
}
}
catch (Exception lookupExcp)
{
//dnsEntry.Unresolvable = true;
dnsResponse.Error = "Exception lookup. " + lookupExcp.Message;
logger.LogError("Exception DNSManager ProcessLookups Lookup (thread, " + threadName + ", hostname=" + hostname + "). " + lookupExcp.GetType().ToString() + "-" + lookupExcp.Message);
}
finally
{
try
{
if (dnsResponse != null)
{
if (lookupRequest.CompleteEvent != null)
{
lookupRequest.CompleteEvent.Set();
}
// Mark any requests for the same hostname complete and fire the completed lookup event where required.
if (lookupRequest.Duplicates != null)
{
foreach (LookupRequest duplicateRequest in lookupRequest.Duplicates)
{
duplicateRequest.CompleteEvent.Set();
}
}
}
LookupRequest lr;
m_inProgressLookups.TryRemove(lookupRequest.id(), out lr);
}
catch (Exception excp)
{
logger.LogError("Exception DNSManager ProcessLookup Adding DNS Response. " + excp.Message);
}
}
}
// No more lookups outstanding, put thread to sleep until a new lookup is required.
m_lookupARE.WaitOne();
}
//logger.LogDebug("Thread " + threadName + " shutdown.");
}
catch (Exception excp)
{
logger.LogError("Exception DNSManager ProcessLookups. " + excp.Message);
}
finally
{
if (m_close)
{
m_lookupARE.Set();
}
//logger.LogDebug("DNSManager thread shutdown.");
}
}