/// <summary>
/// Connects to sepcified host.
/// </summary>
/// <param name="localEndpoint">Sets local endpoint. Pass null, to use default.</param>
/// <param name="host">Host name or IP address.</param>
/// <param name="port">Port where to connect.</param>
/// <param name="ssl">Specifies if to connected via SSL. Default SMTP port is 25 and SSL port is 465.</param>
public void Connect(IPEndPoint localEndpoint, string host, int port, bool ssl)
{
m_pSocket = new SocketEx();
if (localEndpoint != null)
{
m_pSocket.Bind(localEndpoint);
}
// Create logger
if (SessionLog != null)
{
m_pLogger = new SocketLogger(m_pSocket.RawSocket, SessionLog);
m_pLogger.SessionID = Guid.NewGuid().ToString();
m_pSocket.Logger = m_pLogger;
}
if (host.IndexOf("@") == -1)
{
m_pSocket.Connect(host, port, ssl);
}
else
{
//---- Parse e-domain -------------------------------//
string domain = host;
// eg. Ivx <*****@*****.**>
if (domain.IndexOf("<") > -1 && domain.IndexOf(">") > -1)
{
domain = domain.Substring(domain.IndexOf("<") + 1,
domain.IndexOf(">") - domain.IndexOf("<") - 1);
}
if (domain.IndexOf("@") > -1)
{
domain = domain.Substring(domain.LastIndexOf("@") + 1);
}
if (domain.Trim().Length == 0)
{
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Destination address '" + host + "' is invalid, aborting !");
}
throw new Exception("Destination address '" + host + "' is invalid, aborting !");
}
//--- Get MX record -------------------------------------------//
Dns_Client dns = new Dns_Client();
Dns_Client.DnsServers = m_pDnsServers;
DnsServerResponse dnsResponse = dns.Query(domain, QTYPE.MX);
bool connected = false;
switch (dnsResponse.ResponseCode)
{
case RCODE.NO_ERROR:
DNS_rr_MX[] mxRecords = dnsResponse.GetMXRecords();
// Try all available hosts by MX preference order, if can't connect specified host.
foreach (DNS_rr_MX mx in mxRecords)
{
try
{
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Connecting with mx record to: " + mx.Host);
}
m_pSocket.Connect(mx.Host, port, ssl);
connected = true;
break;
}
catch (Exception x)
{
// Just skip and let for to try next host.
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Failed connect to: " + mx.Host + " error:" +
x.Message);
}
}
}
// None of MX didn't connect
if (mxRecords.Length > 0 && !connected)
{
throw new Exception("Destination email server is down");
}
/* Rfc 2821 5
If no MX records are found, but an A RR is found, the A RR is treated as
if it was associated with an implicit MX RR, with a preference of 0,
pointing to that host.
*/
if (!connected)
{
// Try to connect with A record
IPAddress[] ipEntry = null;
try
{
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("No mx record, trying to get A record for: " +
domain);
}
ipEntry = Dns_Client.Resolve(domain);
}
catch
{
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Invalid domain,no MX or A record: " + domain);
}
throw new Exception("Invalid domain,no MX or A record: " + domain);
}
try
{
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Connecting with A record to:" + domain);
}
m_pSocket.Connect(domain, port, ssl);
}
catch
{
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Failed connect to:" + domain);
}
throw new Exception("Destination email server is down");
}
}
break;
case RCODE.NAME_ERROR:
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Invalid domain,no MX or A record: " + domain);
}
throw new Exception("Invalid domain,no MX or A record: " + domain);
case RCODE.SERVER_FAILURE:
if (m_pLogger != null)
{
m_pLogger.AddTextEntry("Dns server unvailable.");
}
throw new Exception("Dns server unvailable.");
}
}
/*
* Notes: Greeting may be single or multiline response.
*
* Examples:
* 220<SP>SMTP server ready<CRLF>
*
* 220-SMTP server ready<CRLF>
* 220-Addtitional text<CRLF>
* 220<SP>final row<CRLF>
*
*/
// Read server response
string responseLine = m_pSocket.ReadLine(1000);
while (!responseLine.StartsWith("220 "))
{
// If lisne won't start with 220, then its error response
if (!responseLine.StartsWith("220"))
{
throw new Exception(responseLine);
}
responseLine = m_pSocket.ReadLine(1000);
}
m_Connected = true;
}
/// <exception cref="System.IO.IOException"></exception>
internal virtual void Ssn139()
{
Name calledName = new Name(Address.FirstCalledName(), 0x20, null);
do
{
Socket = new SocketEx(AddressFamily.InterNetwork,
SocketType.Stream,
ProtocolType.Tcp);
//TCPローカルポートは、毎回空いているものを使う。
//https://blogs.msdn.microsoft.com/dgorti/2005/09/18/only-one-usage-of-each-socket-address-protocolnetwork-addressport-is-normally-permitted/
Socket.Bind(new IPEndPoint(LocalAddr, 0));
Socket.Connect(new IPEndPoint(IPAddress.Parse(Address.GetHostAddress()),
139),
SmbConstants.ConnTimeout);
Socket.SoTimeOut = SmbConstants.SoTimeout;
Out = Socket.GetOutputStream();
In = Socket.GetInputStream();
SessionServicePacket ssp = new SessionRequestPacket(calledName,
NbtAddress.GetLocalName());
Out.Write(Sbuf, 0, ssp.WriteWireFormat(Sbuf, 0));
if (Readn(In, Sbuf, 0, 4) < 4)
{
try
{
//Socket.`Close` method deleted
//Socket.Close();
Socket.Dispose();
}
catch (IOException)
{
}
throw new SmbException("EOF during NetBIOS session request");
}
switch (Sbuf[0] & 0xFF)
{
case SessionServicePacket.PositiveSessionResponse:
{
if (Log.Level >= 4)
{
Log.WriteLine("session established ok with " + Address);
}
return;
}
case SessionServicePacket.NegativeSessionResponse:
{
int errorCode = In.Read() & 0xFF;
switch (errorCode)
{
case NbtException.CalledNotPresent:
case NbtException.NotListeningCalled:
{
//Socket.`Close` method deleted
//Socket.Close();
Socket.Dispose();
break;
}
default:
{
Disconnect(true);
throw new NbtException(NbtException.ErrSsnSrvc,
errorCode);
}
}
break;
}
case -1:
{
Disconnect(true);
throw new NbtException(NbtException.ErrSsnSrvc,
NbtException.ConnectionRefused);
}
default:
{
Disconnect(true);
throw new NbtException(NbtException.ErrSsnSrvc, 0);
}
}
}while ((calledName.name = Address.NextCalledName()) != null);
throw new IOException("Failed to establish session with " + Address);
}
