private void ProcessPacket(SessionPacket packet, ref ConnectionState state)
{
if (packet is SessionMessagePacket)
{
// Note: To be compatible with SMB2 specifications, we must accept SMB_COM_NEGOTIATE.
// We will disconnect the connection if m_enableSMB1 == false and the client does not support SMB2.
bool acceptSMB1 = (state.Dialect == SMBDialect.NotSet || state.Dialect == SMBDialect.NTLM012);
bool acceptSMB2 = (m_enableSMB2 && (state.Dialect == SMBDialect.NotSet || state.Dialect == SMBDialect.SMB202 || state.Dialect == SMBDialect.SMB210 || state.Dialect == SMBDialect.SMB300));
if (SMB1Header.IsValidSMB1Header(packet.Trailer))
{
if (!acceptSMB1)
{
state.LogToServer(Severity.Verbose, "Rejected SMB1 message");
state.ClientSocket.Close();
return;
}
SMB1Message message = null;
try
{
message = SMB1Message.GetSMB1Message(packet.Trailer);
}
catch (Exception ex)
{
state.LogToServer(Severity.Warning, "Invalid SMB1 message: " + ex.Message);
state.ClientSocket.Close();
return;
}
state.LogToServer(Severity.Verbose, "SMB1 message received: {0} requests, First request: {1}, Packet length: {2}", message.Commands.Count, message.Commands[0].CommandName.ToString(), packet.Length);
if (state.Dialect == SMBDialect.NotSet && m_enableSMB2)
{
// Check if the client supports SMB 2
List <string> smb2Dialects = SMB2.NegotiateHelper.FindSMB2Dialects(message);
if (smb2Dialects.Count > 0)
{
SMB2Command response = SMB2.NegotiateHelper.GetNegotiateResponse(smb2Dialects, m_securityProvider, state, m_transport, m_serverGuid, m_serverStartTime);
if (state.Dialect != SMBDialect.NotSet)
{
state = new SMB2ConnectionState(state);
m_connectionManager.AddConnection(state);
}
EnqueueResponse(state, response);
return;
}
}
if (m_enableSMB1)
{
ProcessSMB1Message(message, ref state);
}
else
{
// [MS-SMB2] 3.3.5.3.2 If the string is not present in the dialect list and the server does not implement SMB,
// the server MUST disconnect the connection [..] without sending a response.
state.LogToServer(Severity.Verbose, "Rejected SMB1 message");
state.ClientSocket.Close();
}
}
else if (SMB2Header.IsValidSMB2Header(packet.Trailer))
{
if (!acceptSMB2)
{
state.LogToServer(Severity.Verbose, "Rejected SMB2 message");
state.ClientSocket.Close();
return;
}
List <SMB2Command> requestChain;
try
{
requestChain = SMB2Command.ReadRequestChain(packet.Trailer, 0);
}
catch (Exception ex)
{
state.LogToServer(Severity.Warning, "Invalid SMB2 request chain: " + ex.Message);
state.ClientSocket.Close();
return;
}
state.LogToServer(Severity.Verbose, "SMB2 request chain received: {0} requests, First request: {1}, Packet length: {2}", requestChain.Count, requestChain[0].CommandName.ToString(), packet.Length);
ProcessSMB2RequestChain(requestChain, ref state);
}
else
{
state.LogToServer(Severity.Warning, "Invalid SMB message");
state.ClientSocket.Close();
}
}
else if (packet is SessionRequestPacket && m_transport == SMBTransportType.NetBiosOverTCP)
{
PositiveSessionResponsePacket response = new PositiveSessionResponsePacket();
state.SendQueue.Enqueue(response);
}
else if (packet is SessionKeepAlivePacket && m_transport == SMBTransportType.NetBiosOverTCP)
{
// [RFC 1001] NetBIOS session keep alives do not require a response from the NetBIOS peer
}
else
{
state.LogToServer(Severity.Warning, "Inappropriate NetBIOS session packet");
state.ClientSocket.Close();
return;
}
}