private static IPAddress GetAnswer()
{
try
{
var dnsClient = new DnsQuery
{
Servers = new ArrayList {
new IPEndPoint(IPAddress.Parse(@"8.8.8.8"), 53)
},
Domain = @"www.google.com",
};
if (dnsClient.Send())
{
if (dnsClient.Response.Answers[0] is Address ip)
{
return(ip.IP);
}
}
return(null);
}
catch
{
return(null);
}
}
private static IPAddress ResolveAddress(string hostname, IPEndPoint[] servers, bool ipv6)
{
try
{
Types[] types = ipv6 ? new Types[] { Types.AAAA, Types.A } : new Types[] { Types.A, Types.AAAA };
for (int i = 0; i < types.Length; ++i)
{
DnsQuery dns = new DnsQuery(hostname, types[i]);
dns.RecursionDesired = true;
dns.Servers.AddRange(servers);
if (dns.Send())
{
int len = dns.Response.Answers.Count;
if (len > 0)
{
for (int j = 0; j < len; ++j)
{
if (((ResourceRecord)dns.Response.Answers[j]).Type != types[i])
{
continue;
}
return(((Address)dns.Response.Answers[j]).IP);
}
}
}
}
}
catch
{
}
try
{
IPAddress[] ips = System.Net.Dns.GetHostAddresses(hostname);
if (ips.Length <= 0)
{
return(null);
}
return(ips[0]);
}
catch (Exception)
{
return(null);
}
}
public static IPAddress _QueryDns(string host, string dns_servers, bool IPv6_first = false)
{
IPAddress ret_ipAddress = null;
{
if (!string.IsNullOrEmpty(dns_servers))
{
OpenDNS.Types[] types;
if (IPv6_first)
{
types = new Types[] { Types.AAAA, Types.A }
}
;
else
{
types = new Types[] { Types.A, Types.AAAA }
};
string[] _dns_server = dns_servers.Split(',');
List <IPEndPoint> dns_server = new List <IPEndPoint>();
List <IPEndPoint> local_dns_server = new List <IPEndPoint>();
foreach (string server_str in _dns_server)
{
IPAddress ipAddress = null;
string server = server_str.Trim(' ');
int index = server.IndexOf(':');
string ip = null;
string port = null;
if (index >= 0)
{
if (server.StartsWith("["))
{
int ipv6_end = server.IndexOf(']', 1);
if (ipv6_end >= 0)
{
ip = server.Substring(1, ipv6_end - 1);
index = server.IndexOf(':', ipv6_end);
if (index == ipv6_end + 1)
{
port = server.Substring(index + 1);
}
}
}
else
{
ip = server.Substring(0, index);
port = server.Substring(index + 1);
}
}
else
{
index = server.IndexOf(' ');
if (index >= 0)
{
ip = server.Substring(0, index);
port = server.Substring(index + 1);
}
else
{
ip = server;
}
}
if (ip != null && IPAddress.TryParse(ip, out ipAddress))
{
int i_port = 53;
if (port != null)
{
int.TryParse(port, out i_port);
}
dns_server.Add(new IPEndPoint(ipAddress, i_port));
//dns_server.Add(port == null ? ip : ip + " " + port);
}
}
for (int query_i = 0; query_i < types.Length; ++query_i)
{
DnsQuery dns = new DnsQuery(host, types[query_i]);
dns.RecursionDesired = true;
foreach (IPEndPoint server in dns_server)
{
dns.Servers.Add(server);
}
if (dns.Send())
{
int count = dns.Response.Answers.Count;
if (count > 0)
{
for (int i = 0; i < count; ++i)
{
if (((ResourceRecord)dns.Response.Answers[i]).Type != types[query_i])
{
continue;
}
return(((OpenDNS.Address)dns.Response.Answers[i]).IP);
}
}
}
}
}
{
try
{
GetHostEntryHandler callback = new GetHostEntryHandler(Dns.GetHostEntry);
IAsyncResult result = callback.BeginInvoke(host, null, null);
if (result.AsyncWaitHandle.WaitOne(10000, true))
{
IPHostEntry ipHostEntry = callback.EndInvoke(result);
foreach (IPAddress ad in ipHostEntry.AddressList)
{
if (ad.AddressFamily == AddressFamily.InterNetwork)
{
return(ad);
}
}
foreach (IPAddress ad in ipHostEntry.AddressList)
{
return(ad);
}
}
}
catch
{
}
}
}
return(ret_ipAddress);
}
public static IPAddress QueryDns(string host, string dns_servers, bool IPv6_first = false)
{
IPAddress ret_ipAddress = null;
{
if (dns_servers != null && dns_servers.Length > 0)
{
OpenDNS.Types[] types;
if (IPv6_first)
{
types = new Types[] { Types.AAAA, Types.A }
}
;
else
{
types = new Types[] { Types.A, Types.AAAA }
};
string[] _dns_server = dns_servers.Split(',');
List <string> dns_server = new List <string>();
List <string> local_dns_server = new List <string>();
foreach (string ip in _dns_server)
{
IPAddress ipAddress = null;
if (IPAddress.TryParse(ip, out ipAddress))
{
dns_server.Add(ip);
}
}
for (int query_i = 0; query_i < types.Length; ++query_i)
{
DnsQuery dns = new DnsQuery(host, types[query_i]);
dns.RecursionDesired = true;
foreach (string server in dns_server)
{
dns.Servers.Add(server);
}
if (dns.Send())
{
int count = dns.Response.Answers.Count;
if (count > 0)
{
for (int i = 0; i < count; ++i)
{
if (((ResourceRecord)dns.Response.Answers[i]).Type != types[query_i])
{
continue;
}
return(((OpenDNS.Address)dns.Response.Answers[i]).IP);
}
}
}
}
}
{
try
{
GetHostEntryHandler callback = new GetHostEntryHandler(Dns.GetHostEntry);
IAsyncResult result = callback.BeginInvoke(host, null, null);
if (result.AsyncWaitHandle.WaitOne(5, true))
{
foreach (IPAddress ad in callback.EndInvoke(result).AddressList)
{
return(ad);
//if (ad.AddressFamily == AddressFamily.InterNetwork)
//{
// return ad;
//}
}
}
}
catch
{
}
}
}
return(ret_ipAddress);
}
private static IPAddress _QueryDns(string host, string dnsServers, bool IPv6_first = false)
{
if (!string.IsNullOrEmpty(dnsServers))
{
var types = IPv6_first ? new[] { Types.AAAA, Types.A } : new[] { Types.A, Types.AAAA };
var dnsServerStr = dnsServers.Split(',');
var dnsServer = new List <IPEndPoint>();
foreach (var serverStr in dnsServerStr)
{
var server = serverStr.Trim(' ');
var index = server.IndexOf(':');
string ip = null;
string port = null;
if (index >= 0)
{
if (server.StartsWith("["))
{
var ipv6_end = server.IndexOf(']', 1);
if (ipv6_end >= 0)
{
ip = server.Substring(1, ipv6_end - 1);
index = server.IndexOf(':', ipv6_end);
if (index == ipv6_end + 1)
{
port = server.Substring(index + 1);
}
}
}
else
{
ip = server.Substring(0, index);
port = server.Substring(index + 1);
}
}
else
{
index = server.IndexOf(' ');
if (index >= 0)
{
ip = server.Substring(0, index);
port = server.Substring(index + 1);
}
else
{
ip = server;
}
}
if (ip != null && IPAddress.TryParse(ip, out var ipAddress))
{
var iPort = 53;
if (port != null)
{
int.TryParse(port, out iPort);
}
dnsServer.Add(new IPEndPoint(ipAddress, iPort));
}
}
foreach (var type in types)
{
var dns = new DnsQuery(host, type)
{
RecursionDesired = true
};
foreach (var server in dnsServer)
{
dns.Servers.Add(server);
}
if (dns.Send())
{
var count = dns.Response.Answers.Count;
if (count > 0)
{
for (var i = 0; i < count; ++i)
{
if (((ResourceRecord)dns.Response.Answers[i]).Type != type)
{
continue;
}
return(((Address)dns.Response.Answers[i]).IP);
}
}
}
}
}
try
{
var callback = new GetHostEntryHandler(Dns.GetHostEntry);
var result = callback.BeginInvoke(host, null, null);
if (result.AsyncWaitHandle.WaitOne(10000, true))
{
var ipHostEntry = callback.EndInvoke(result);
foreach (var ad in ipHostEntry.AddressList)
{
if (ad.AddressFamily == AddressFamily.InterNetwork)
{
return(ad);
}
}
foreach (var ad in ipHostEntry.AddressList)
{
return(ad);
}
}
}
catch
{
// ignored
}
return(null);
}
