private void Client_Received(Object sender, ReceivedEventArgs e)
{
if (e.Length == 0)
{
return;
}
var dns = DNSEntity.Read(e.Stream, Client.Local.IsTcp);
OnReceive(dns);
}
private void Client_Received(Object sender, ReceivedEventArgs e)
{
var pk = e.Packet;
if (pk.Total == 0)
{
return;
}
var dns = DNSEntity.Read(pk.GetStream(), Client.Local.IsTcp);
OnReceive(dns);
}
/// <summary>接收处理</summary>
/// <param name="session"></param>
/// <param name="stream"></param>
protected override void OnReceive(INetSession session, Stream stream)
{
var isTcp = session.Session.Local.IsTcp;
// 解析
var request = DNSEntity.Read(stream, isTcp);
var response = Request(session, request);
if (response != null)
{
response.Header.ID = request.Header.ID;
Response(session, request, response);
}
session.Dispose();
}
DNSEntity GetDNS(String key, DNSEntity request)
{
// 请求父级代理
NetUri parent = null;
Byte[] data = null;
ISocketClient client = null;
NetUri[] us = null;
lock (Parents) { us = Parents.ToArray(); }
foreach (var item in us)
{
WriteLog("GetDNS key={0} {1}", key, item);
client = item.CreateRemote();
// 如果是PTR请求
if (request.IsPTR)
{
// 复制一份，防止修改外部
request = new DNSEntity().CloneFrom(request);
var ptr = request.GetAnswer(true) as DNS_PTR;
if (ptr != null)
{
ptr.Address = item.Address;
}
}
try
{
client.Timeout = 1000;
client.Send(request.GetStream(item.IsTcp));
data = client.Receive();
if (data != null && data.Length > 0)
{
parent = item;
break;
}
}
catch { }
}
if (data == null || data.Length < 1)
{
return(null);
}
// 调到第一位
if (Parents.Count > 1 && Parents[0] != parent)
{
lock (Parents)
{
if (Parents.Count > 1 && Parents[0] != parent)
{
Parents.Remove(parent);
Parents.Insert(0, parent);
}
}
}
DNSEntity response = null;
try
{
// 解析父级代理返回的数据
response = DNSEntity.Read(data, parent.IsTcp);
// 处理，修改
WriteLog("{0} 返回 {1}", parent, response);
}
catch (Exception ex)
{
String file = String.Format("dns_{0:MMddHHmmss}.bin", DateTime.Now);
XTrace.WriteLine("解析父级代理返回数据出错！数据保存于" + file + "。" + ex.Message);
File.WriteAllBytes(file, data);
}
if (OnNew != null)
{
var e = new DNSEventArgs {
Request = request, Response = response, Session = client
};
OnNew(this, e);
}
return(response);
}
internal DNSEntity Invoke(DNSEntity request, Boolean isQuery)
{
var attempts = 0;
while (attempts <= _maxRetryAttemps)
{
var bytes = request.GetStream(false).ReadBytes();
if (bytes.Length > 512)
{
throw new ArgumentException("RFC 1035 2.3.4 states that the maximum size of a UDP datagram is 512 octets (bytes).");
}
Socket socket = null;
try
{
socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)
{
ReceiveTimeout = 300
};
//socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 300);
socket.SendTo(bytes, bytes.Length, SocketFlags.None, new IPEndPoint(IPAddress.Parse("192.168.178.255"), 137));
if (!isQuery)
{
return(null);
}
// Messages carried by UDP are restricted to 512 bytes (not counting the IP
// or UDP headers). Longer messages are truncated and the TC bit is set in
// the header. (RFC 1035 4.2.1)
var responseMessage = new Byte[512];
//int numBytes = socket.Receive(responseMessage);
var ep = (EndPoint) new IPEndPoint(new IPAddress(4294967295), 137);
var numBytes = socket.ReceiveFrom(responseMessage, ref ep);
if (numBytes == 0 || numBytes > 512)
{
throw new Exception("RFC 1035 2.3.4 states that the maximum size of a UDP datagram is 512 octets (bytes).");
}
//DnsReader br = new DnsReader(responseMessage);
//DnsResponse res = new DnsResponse(br);
var rs = DNSEntity.Read(responseMessage, false);
if (request.Header.ID == rs.Header.ID)
{
return(rs);
}
attempts++;
}
catch
{
attempts++;
}
finally
{
socket.Close();
socket = null;
}
}
throw new Exception("Could not resolve the query (" + attempts + " attempts).");
}