/// <summary>
/// Begin send a query to a domain name server to perform a
/// lookup on the specified domian and return the records.
/// </summary>
/// <param name="domain">The domain to get records for.</param>
/// <param name="dnsType">The dns record type to return.</param>
/// <param name="dnsClass">The class to search in.</param>
/// <param name="callback">The asynchronous call back method.</param>
/// <param name="state">The state object value.</param>
/// <returns>The asynchronous result.</returns>
public virtual IAsyncResult BeginQuery(string domain, Nequeo.Net.Dns.DnsType dnsType,
Nequeo.Net.Dns.DnsClass dnsClass, AsyncCallback callback, object state)
{
// Return an AsyncResult.
return(new AsyncDnsQueryRequest(domain, dnsType,
dnsClass, this, callback, state));
}
/// <summary>
/// Construct the question from parameters, checking for safety
/// </summary>
/// <param name="domain">the domain name to query eg. bigdevelopments.co.uk</param>
/// <param name="dnsType">the QTYPE of query eg. DnsType.MX</param>
/// <param name="dnsClass">the CLASS of query, invariably DnsClass.IN</param>
internal Question(string domain, Nequeo.Net.Dns.DnsType dnsType,
Nequeo.Net.Dns.DnsClass dnsClass)
{
// check the input parameters
if (domain == null)
{
throw new ArgumentNullException("domain");
}
// do a sanity check on the domain name to make sure its legal
if (domain.Length == 0 || domain.Length > 255 || !Regex.IsMatch(domain, @"^[a-z|A-Z|0-9|-|_]{1,63}(\.[a-z|A-Z|0-9|-|_]{1,63})+$"))
{
// domain names can't be bigger tan 255 chars, and individal labels can't be bigger than 63 chars
throw new ArgumentException("The supplied domain name was not in the correct form", "domain");
}
// sanity check the DnsType parameter
if (!Enum.IsDefined(typeof(Nequeo.Net.Dns.DnsType), dnsType) || dnsType == Nequeo.Net.Dns.DnsType.None)
{
throw new ArgumentOutOfRangeException("dnsType", "Not a valid value");
}
// sanity check the DnsClass parameter
if (!Enum.IsDefined(typeof(Nequeo.Net.Dns.DnsClass), dnsClass) || dnsClass == Nequeo.Net.Dns.DnsClass.None)
{
throw new ArgumentOutOfRangeException("dnsClass", "Not a valid value");
}
// just remember the values
_domain = domain;
_dnsType = dnsType;
_dnsClass = dnsClass;
}
/// <summary>
/// Start the asynchronous query request operation.
/// </summary>
/// <param name="domain">The domain to get records for.</param>
/// <param name="dnsType">The dns record type to return.</param>
/// <param name="dnsClass">The class to search in.</param>
/// <param name="client">The current domain name client reference.</param>
/// <param name="callback">The asynchronous call back method.</param>
/// <param name="state">The state object value.</param>
public AsyncDnsQueryRequest(string domain, Nequeo.Net.Dns.DnsType dnsType,
Nequeo.Net.Dns.DnsClass dnsClass, DomainNameClient client, AsyncCallback callback, object state)
: base(callback, state)
{
_client = client;
_domain = domain;
_dnsType = dnsType;
_dnsClass = dnsClass;
ThreadPool.QueueUserWorkItem(new WaitCallback(AsyncQueryRequestThread1));
Thread.Sleep(20);
}
/// <summary>
/// Send a query to a domain name server to perform a
/// lookup on the specified domian and return the records.
/// </summary>
/// <param name="domain">The domain to get records for.</param>
/// <param name="dnsType">The dns record type to return.</param>
/// <param name="dnsClass">The class to search in.</param>
/// <returns>The response object containing the collection
/// of domain name server information.</returns>
public virtual Response Query(string domain, Nequeo.Net.Dns.DnsType dnsType,
Nequeo.Net.Dns.DnsClass dnsClass)
{
// Validate the inputs.
if (String.IsNullOrEmpty(domain))
{
throw new System.ArgumentNullException("Domain can not be null.",
new System.Exception("A valid domain should be specified."));
}
if (String.IsNullOrEmpty(_dnsServer))
{
throw new System.ArgumentNullException("Domain name server can not be null.",
new System.Exception("A valid domain name server should be specified."));
}
_domain = domain;
// create a DNS request
Request request = new Request();
Resolver resolver = new Resolver();
// create a question for this domain and DNS class.
request.AddQuestion(new Question(domain, dnsType, dnsClass));
// send it to the DNS server and get the response
Response response = resolver.Lookup(request, _domain, _dnsPort, _dnsServer, _protocolType, _useIPv4EndPoint);
// If the event has been attached
// send to the client the data through
// the delegate.
if (OnQueryComplete != null)
{
OnQueryComplete(this, response);
}
// Return the response from the server.
return(response);
}
