// Actually checks to see if data can go to the internet (via UDP 53)
private void DoCheckDNSNetwork(object oIn)
{
try
{
StateManager CurState = (StateManager)oIn;
byte[] bIDOut = new byte[8];
// First, try a DNS ping through proxy (whether it's on or not)
EDNSPacket Packet = SendUdpNetworkPacket(g_sProxyIP, g_sIDIP, 53, 0x10, false, bIDOut);
DNSPacket.PacketExplode pe = new DNSPacket.PacketExplode(Packet.GetResponsePacket());
// Retry over TCP if truncated
if (pe.IsTruncated())
{
Packet = SendTcpNetworkPacket(g_sProxyIP, g_sIDIP, 53, 0x10, false, bIDOut);
}
if (Packet.GetResponsePacket().Length > 0)
{
// We got a result through the proxy; all is well
CurState.SetEncryptedState(true);
CurState.SetNetworkState(true, true);
}
else
{
// We did not get a response through the proxy, so encryption is a no-go
CurState.SetEncryptedState(false);
// Try a second DNS ping, this time through the OpenDNS resolver
Packet = SendUdpNetworkPacket(g_sResolverIP, g_sIDIP, 53, 0x10, false, bIDOut);
if (Packet.GetResponsePacket().Length > 0)
{
// We have at least SOME internet connection
CurState.SetNetworkState(true, true);
}
else
{
// We could not reach the network at all
CurState.SetNetworkState(false, true);
}
}
}
catch (Exception Ex)
{
// Do nothing
}
}
// Actually builds, sends, sets the received bytes and returns the whole packet
private EDNSPacket SendUdpNetworkPacket(string sDNSIP, string sIPToResolve, int nPort, byte bType, bool bEDNS, byte[] bMachine_ID)
{
// Create empty EDNS packet
EDNSPacket Packet = new EDNSPacket();
try
{
IPEndPoint Endpoint = new IPEndPoint(IPAddress.Parse(sDNSIP), nPort);
// Send the current machine_id host
if (bEDNS)
Packet.CreateEDNSPacketMachineID(sIPToResolve, bType, bMachine_ID);
else
Packet.CreateDNSPacket(sIPToResolve, bType);
if (Packet.GetPacketLen() > 0)
{
// Create a udp client to send the packet
UdpClient udpGo = new UdpClient();
udpGo.Client.SendTimeout = 2000;
udpGo.Client.ReceiveTimeout = 2000;
udpGo.Send(Packet.GetPacket(), Packet.GetPacket().Length, Endpoint);
//IPEndPoint object will allow us to read datagrams sent from any source.
IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
// Launch Asynchronous
IAsyncResult iarResult = udpGo.BeginReceive(null, null);
// Wait until complete
bool bKill = false;
DateTime dtTimeStart = DateTime.Now;
while (iarResult.IsCompleted == false)
{
// Sleep instead of cycling
System.Threading.Thread.Sleep(100);
// Watchdog, if doesn't return in 5 seconds get out
if (dtTimeStart.AddSeconds(5) < DateTime.Now)
{
bKill = true;
break;
}
}
// This can hang when not happy about a broken connection
if (bKill)
udpGo.Close();
else
Packet.SetReceivePacket(udpGo.EndReceive(iarResult, ref RemoteIpEndPoint));
}
}
catch (Exception Ex)
{
// TODO: Log an exception?
}
// Always just return packet
return Packet;
}
// Actually builds, sends, sets the received bytes and returns the whole packet
private EDNSPacket SendTcpNetworkPacket(string sDNSIP, string sIPToResolve, int nPort, byte bType, bool bEDNS, byte[] bMachine_ID)
{
// Create empty EDNS packet
EDNSPacket Packet = new EDNSPacket();
try
{
// Send the current machine_id host
if (bEDNS)
Packet.CreateEDNSPacketMachineID(sIPToResolve, bType, bMachine_ID);
else
Packet.CreateDNSPacket(sIPToResolve, bType);
if (Packet.GetPacketLen() > 0)
{
// Create a tcp client to send the packet
TcpClient tcpGo = new TcpClient(sDNSIP, nPort);
NetworkStream tcpStream = tcpGo.GetStream();
byte[] packetBytes = Packet.GetPacket();
// Get length bytes in network byte order
byte[] lengthBytes = BitConverter.GetBytes((short)packetBytes.Length);
if (BitConverter.IsLittleEndian) Array.Reverse(lengthBytes);
// Prepend the length to the existing data; TCP DNS seems to require this
byte[] sendBytes = new byte[packetBytes.Length + 2];
Buffer.BlockCopy(lengthBytes, 0, sendBytes, 0, lengthBytes.Length);
Buffer.BlockCopy(packetBytes, 0, sendBytes, 2, packetBytes.Length);
tcpStream.Write(sendBytes, 0, sendBytes .Length);
// Get the response synchronously (hopefully smaller than 2048)
byte[] receiveBuffer = new byte[2048];
int bytesRead = tcpStream.Read(packetBytes, 0, packetBytes.Length);
if (bytesRead > 0)
{
// Trim off that extra length before returning the packet
byte[] buffTrimmed = new byte[bytesRead - 2];
Buffer.BlockCopy(receiveBuffer, 2, buffTrimmed, 0, bytesRead - 2);
Packet.SetReceivePacket(buffTrimmed);
}
tcpStream.Close();
tcpGo.Close();
}
}
catch (Exception Ex)
{
// TODO: Log an exception?
m_Log.Log(Logging.LOGTYPE.DEBUG, "SendTcpNetworkPacket EXCEPTION: " + Ex.Message);
}
// Always just return packet
return Packet;
}
// Actually builds, sends, sets the received bytes and returns the whole packet
private EDNSPacket SendTcpNetworkPacket(string sDNSIP, string sIPToResolve, int nPort, byte bType, bool bEDNS, byte[] bMachine_ID)
{
// Create empty EDNS packet
EDNSPacket Packet = new EDNSPacket();
try
{
// Send the current machine_id host
if (bEDNS)
{
Packet.CreateEDNSPacketMachineID(sIPToResolve, bType, bMachine_ID);
}
else
{
Packet.CreateDNSPacket(sIPToResolve, bType);
}
if (Packet.GetPacketLen() > 0)
{
// Create a tcp client to send the packet
TcpClient tcpGo = new TcpClient(sDNSIP, nPort);
NetworkStream tcpStream = tcpGo.GetStream();
byte[] packetBytes = Packet.GetPacket();
// Get length bytes in network byte order
byte[] lengthBytes = BitConverter.GetBytes((short)packetBytes.Length);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(lengthBytes);
}
// Prepend the length to the existing data; TCP DNS seems to require this
byte[] sendBytes = new byte[packetBytes.Length + 2];
Buffer.BlockCopy(lengthBytes, 0, sendBytes, 0, lengthBytes.Length);
Buffer.BlockCopy(packetBytes, 0, sendBytes, 2, packetBytes.Length);
tcpStream.Write(sendBytes, 0, sendBytes.Length);
// Get the response synchronously (hopefully smaller than 2048)
byte[] receiveBuffer = new byte[2048];
int bytesRead = tcpStream.Read(packetBytes, 0, packetBytes.Length);
if (bytesRead > 0)
{
// Trim off that extra length before returning the packet
byte[] buffTrimmed = new byte[bytesRead - 2];
Buffer.BlockCopy(receiveBuffer, 2, buffTrimmed, 0, bytesRead - 2);
Packet.SetReceivePacket(buffTrimmed);
}
tcpStream.Close();
tcpGo.Close();
}
}
catch (Exception Ex)
{
// TODO: Log an exception?
m_Log.Log(Logging.LOGTYPE.DEBUG, "SendTcpNetworkPacket EXCEPTION: " + Ex.Message);
}
// Always just return packet
return(Packet);
}
// Actually builds, sends, sets the received bytes and returns the whole packet
private EDNSPacket SendUdpNetworkPacket(string sDNSIP, string sIPToResolve, int nPort, byte bType, bool bEDNS, byte[] bMachine_ID)
{
// Create empty EDNS packet
EDNSPacket Packet = new EDNSPacket();
try
{
IPEndPoint Endpoint = new IPEndPoint(IPAddress.Parse(sDNSIP), nPort);
// Send the current machine_id host
if (bEDNS)
{
Packet.CreateEDNSPacketMachineID(sIPToResolve, bType, bMachine_ID);
}
else
{
Packet.CreateDNSPacket(sIPToResolve, bType);
}
if (Packet.GetPacketLen() > 0)
{
// Create a udp client to send the packet
UdpClient udpGo = new UdpClient();
udpGo.Client.SendTimeout = 2000;
udpGo.Client.ReceiveTimeout = 2000;
udpGo.Send(Packet.GetPacket(), Packet.GetPacket().Length, Endpoint);
//IPEndPoint object will allow us to read datagrams sent from any source.
IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
// Launch Asynchronous
IAsyncResult iarResult = udpGo.BeginReceive(null, null);
// Wait until complete
bool bKill = false;
DateTime dtTimeStart = DateTime.Now;
while (iarResult.IsCompleted == false)
{
// Sleep instead of cycling
System.Threading.Thread.Sleep(100);
// Watchdog, if doesn't return in 5 seconds get out
if (dtTimeStart.AddSeconds(5) < DateTime.Now)
{
bKill = true;
break;
}
}
// This can hang when not happy about a broken connection
if (bKill)
{
udpGo.Close();
}
else
{
Packet.SetReceivePacket(udpGo.EndReceive(iarResult, ref RemoteIpEndPoint));
}
}
}
catch (Exception Ex)
{
// TODO: Log an exception?
}
// Always just return packet
return(Packet);
}
