internal static List <string> FindSMB2Dialects(SMBLibrary.SMB1.SMB1Message message)
{
if (message.Commands.Count > 0 && message.Commands[0] is SMBLibrary.SMB1.NegotiateRequest)
{
SMBLibrary.SMB1.NegotiateRequest request = (SMBLibrary.SMB1.NegotiateRequest)message.Commands[0];
return(FindSMB2Dialects(request));
}
return(new List <string>());
}
/// <summary>
/// Some broken NATs will reply to TCP KeepAlive even after the client initiating the connection has long gone,
/// This methods prevent such connections from hanging around indefinitely by sending an unsolicited ECHO response to make sure the connection is still alive.
/// </summary>
public void SendSMBKeepAlive(TimeSpan inactivityDuration)
{
List <ConnectionState> connections = new List <ConnectionState>(m_activeConnections);
foreach (ConnectionState connection in connections)
{
if (connection.LastReceiveDT.Add(inactivityDuration) < DateTime.UtcNow &&
connection.LastSendDT.Add(inactivityDuration) < DateTime.UtcNow)
{
if (connection is SMB1ConnectionState)
{
// [MS-CIFS] Clients SHOULD, at minimum, send an SMB_COM_ECHO to the server every few minutes.
// This means that an unsolicited SMB_COM_ECHO reply is not likely to be sent on a connection that is alive.
SMBLibrary.SMB1.SMB1Message echoReply = SMB1.EchoHelper.GetUnsolicitedEchoReply();
SMBServer.EnqueueMessage(connection, echoReply);
}
else if (connection is SMB2ConnectionState)
{
SMBLibrary.SMB2.EchoResponse echoResponse = SMB2.EchoHelper.GetUnsolicitedEchoResponse();
SMBServer.EnqueueResponse(connection, echoResponse);
}
}
}
}
