public static string GetCacheKey(DnsQuestion question, NameServer server)
{
if (question == null)
{
throw new ArgumentNullException(nameof(question));
}
if (server == null)
{
throw new ArgumentNullException(nameof(server));
}
return(string.Concat(server.Endpoint.Address.ToString(), "#", server.Endpoint.Port.ToString(), "_", question.QueryName.Value, ":", (short)question.QuestionClass, ":", (short)question.QuestionType));
}
private void DisableServer(NameServer server)
{
lock (_endpointLock)
{
server.Enabled = false;
if (_endpoints.Count(p => p.Enabled == true) == 0)
{
// reset all servers to try again...
_endpoints.ToList().ForEach(p => p.Enabled = true);
}
}
}
internal DnsQueryResponse(DnsResponseMessage dnsResponseMessage, NameServer nameServer)
{
if (dnsResponseMessage == null)
{
throw new ArgumentNullException(nameof(dnsResponseMessage));
}
Header = dnsResponseMessage.Header;
MessageSize = dnsResponseMessage.MessageSize;
Questions = dnsResponseMessage.Questions;
Answers = dnsResponseMessage.Answers;
Additionals = dnsResponseMessage.Additionals;
Authorities = dnsResponseMessage.Authorities;
NameServer = nameServer;
}
internal DnsQueryResponse(DnsResponseMessage dnsResponseMessage, NameServer nameServer, DnsQuerySettings settings)
{
if (dnsResponseMessage == null)
{
throw new ArgumentNullException(nameof(dnsResponseMessage));
}
Header = dnsResponseMessage.Header;
MessageSize = dnsResponseMessage.MessageSize;
Questions = dnsResponseMessage.Questions.ToArray();
Answers = dnsResponseMessage.Answers.ToArray();
Additionals = dnsResponseMessage.Additionals.ToArray();
Authorities = dnsResponseMessage.Authorities.ToArray();
NameServer = nameServer ?? throw new ArgumentNullException(nameof(nameServer));
Settings = settings;
}
internal DnsQueryResponse(DnsResponseMessage dnsResponseMessage, NameServer nameServer, LookupClientAudit audit)
{
if (dnsResponseMessage == null)
{
throw new ArgumentNullException(nameof(dnsResponseMessage));
}
Header = dnsResponseMessage.Header;
MessageSize = dnsResponseMessage.MessageSize;
Questions = dnsResponseMessage.Questions.ToArray();
Answers = dnsResponseMessage.Answers.ToArray();
Additionals = dnsResponseMessage.Additionals.ToArray();
Authorities = dnsResponseMessage.Authorities.ToArray();
NameServer = nameServer ?? throw new ArgumentNullException(nameof(nameServer));
Audit = audit ?? throw new ArgumentNullException(nameof(audit));
}
private IEnumerable <NameServer> GetNextServers()
{
IEnumerable <NameServer> servers = null;
if (_endpoints.Count > 1)
{
servers = _endpoints.Where(p => p.Enabled);
NameServer server = null;
if (_endpoints.TryDequeue(out server))
{
_endpoints.Enqueue(server);
}
}
else
{
servers = _endpoints;
}
return(servers);
}
private void HandleOptRecords(Audit audit, NameServer serverInfo, DnsResponseMessage response)
{
var opt = response.Additionals.OfType <OptRecord>().FirstOrDefault();
if (opt != null)
{
if (EnableAuditTrail)
{
audit.AuditOptPseudo();
}
serverInfo.SupportedUdpPayloadSize = opt.UdpSize;
// TODO: handle opt records and remove them later
response.Additionals.Remove(opt);
if (EnableAuditTrail)
{
audit.AuditEdnsOpt(opt.UdpSize, opt.Version, opt.ResponseCodeEx);
}
}
}
public LookupClient()
: this(NameServer.ResolveNameServers()?.ToArray())
{
}
/// <summary> /// Gets the readonly representation of this message which can be returned. /// </summary> public DnsQueryResponse AsQueryResponse(NameServer nameServer) => new DnsQueryResponse(this, nameServer, Audit);
/// <summary> /// Gets the readonly representation of this message which can be returned. /// </summary> public DnsQueryResponse AsQueryResponse(NameServer nameServer, DnsQuerySettings settings) => new DnsQueryResponse(this, nameServer, Audit, settings);
public void AuditRetryNextServer(NameServer current)
{
_auditWriter.AppendLine();
_auditWriter.AppendLine($"; SERVER: {current.Endpoint.Address}#{current.Endpoint.Port} failed; Retrying with the next server.");
}
/// <summary>
/// Creates a new instance of <see cref="LookupClientOptions"/> with one name server.
/// <see cref="IPAddress"/> or <see cref="IPEndPoint"/> can be used as well thanks to implicit conversion.
/// </summary>
/// <param name="nameServer">The name servers.</param>
public LookupClientOptions(NameServer nameServer)
: base(nameServer)
{
}
/// <summary>
/// Creates a new instance of <see cref="DnsQueryOptions"/> with one name server.
/// <see cref="IPAddress"/> or <see cref="IPEndPoint"/> can be used as well thanks to implicit conversion.
/// </summary>
/// <param name="nameServer">The name servers.</param>
public DnsQueryOptions(NameServer nameServer)
: this(new[] { nameServer })
{
}
// TODO: evalualte if defaulting resolveNameServers to false here and in the query plan, fall back to configured nameservers of the client
/// <summary>
/// Creates a new instance of <see cref="DnsQueryOptions"/> without name servers.
/// </summary>
/// <remarks>
/// If no nameservers are configured, a query will fallback to the nameservers already configured on the <see cref="LookupClient"/> instance.
/// </remarks>
/// <param name="resolveNameServers">If set to <c>true</c>, <see cref="NameServer.ResolveNameServers(bool, bool)"/>
/// will be used to get a list of nameservers.</param>
public DnsQueryOptions(bool resolveNameServers = false)
: this(resolveNameServers ? NameServer.ResolveNameServers() : null)
{
AutoResolvedNameServers = resolveNameServers;
}
