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// System.Net.Dns.cs
//
// Author: Mads Pultz (mpultz@diku.dk)
// Author: Lawrence Pit (loz@cable.a2000.nl)
//
// (C) Mads Pultz, 2001
using System;
using System.Net.Sockets;
using System.Text;
using System.Collections;
using System.Threading;
using System.Runtime.CompilerServices;
using System.Runtime.Remoting.Messaging;
namespace System.Net {
public sealed class Dns {
private Dns () {}
private delegate IPHostEntry GetHostByNameCallback (string hostName);
private delegate IPHostEntry ResolveCallback (string hostName);
public static IAsyncResult BeginGetHostByName (string hostName,
AsyncCallback requestCallback, object stateObject)
{
if (hostName == null)
throw new ArgumentNullException();
GetHostByNameCallback c = new GetHostByNameCallback (GetHostByName);
return c.BeginInvoke (hostName, requestCallback, stateObject);
}
public static IAsyncResult BeginResolve (string hostName,
AsyncCallback requestCallback, object stateObject)
{
if (hostName == null)
throw new ArgumentNullException();
ResolveCallback c = new ResolveCallback (Resolve);
return c.BeginInvoke (hostName, requestCallback, stateObject);
}
public static IPHostEntry EndGetHostByName (IAsyncResult asyncResult) {
if (asyncResult == null)
throw new ArgumentNullException ("asyncResult");
AsyncResult async = (AsyncResult) asyncResult;
GetHostByNameCallback cb = (GetHostByNameCallback) async.AsyncDelegate;
asyncResult.AsyncWaitHandle.WaitOne ();
return cb.EndInvoke(asyncResult);
}
public static IPHostEntry EndResolve (IAsyncResult asyncResult) {
if (asyncResult == null)
throw new ArgumentNullException ("asyncResult");
AsyncResult async = (AsyncResult) asyncResult;
ResolveCallback cb = (ResolveCallback) async.AsyncDelegate;
asyncResult.AsyncWaitHandle.WaitOne ();
return cb.EndInvoke(asyncResult);
}
[MethodImplAttribute(MethodImplOptions.InternalCall)]
private extern static bool GetHostByName_internal(string host, out string h_name, out string[] h_aliases, out string[] h_addr_list);
[MethodImplAttribute(MethodImplOptions.InternalCall)]
private extern static bool GetHostByAddr_internal(string addr, out string h_name, out string[] h_aliases, out string[] h_addr_list);
private static IPHostEntry hostent_to_IPHostEntry(string h_name, string[] h_aliases, string[] h_addrlist) {
IPHostEntry he = new IPHostEntry();
IPAddress[] addrlist = new IPAddress[h_addrlist.Length];
he.HostName=h_name;
he.Aliases=h_aliases;
for(int i=0; i<h_addrlist.Length; i++) {
addrlist[i]=IPAddress.Parse(h_addrlist[i]);
}
he.AddressList=addrlist;
return(he);
}
public static IPHostEntry GetHostByAddress(IPAddress address) {
if (address == null)
throw new ArgumentNullException();
return GetHostByAddress(address.ToString());
}
public static IPHostEntry GetHostByAddress(string address) {
if (address == null) {
throw new ArgumentNullException();
}
string h_name;
string[] h_aliases, h_addrlist;
bool ret = GetHostByAddr_internal(address, out h_name,
out h_aliases,
out h_addrlist);
if (ret == false) {
throw new SocketException(11001);
}
return(hostent_to_IPHostEntry(h_name, h_aliases,
h_addrlist));
}
public static IPHostEntry GetHostByName(string hostName) {
if (hostName == null)
throw new ArgumentNullException();
string h_name;
string[] h_aliases, h_addrlist;
bool ret = GetHostByName_internal(hostName, out h_name,
out h_aliases,
out h_addrlist);
if (ret == false)
throw new SocketException(11001);
return(hostent_to_IPHostEntry(h_name, h_aliases,
h_addrlist));
}
/// <summary>
/// This method returns the host name associated with the local host.
/// </summary>
public static string GetHostName() {
IPHostEntry h = GetHostByAddress("127.0.0.1");
return h.HostName;
}
/// <summary>
/// This method resolves a DNS-style host name or IP
/// address.
/// </summary>
/// <param name=hostName>
/// A string containing either a DNS-style host name (e.g.
/// www.go-mono.com) or IP address (e.g. 129.250.184.233).
/// </param>
public static IPHostEntry Resolve(string hostName) {
if (hostName == null)
throw new ArgumentNullException();
return GetHostByName (hostName);
}
}
}
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