/* Copyright (C) 2017 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
*
* You can redistribute this program and/or modify it under the terms of
* the GNU Lesser Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later version.
*/
using System;
using System.Collections.Generic;
using SMBLibrary.NetBios;
using SMBLibrary.Server.SMB2;
using SMBLibrary.SMB2;
using Utilities;
namespace SMBLibrary.Server
{
public partial class SMBServer
{
private void ProcessSMB2RequestChain(List<SMB2Command> requestChain, ref ConnectionState state)
{
List<SMB2Command> responseChain = new List<SMB2Command>();
FileID? fileID = null;
foreach (SMB2Command request in requestChain)
{
if (request.Header.IsRelatedOperations && fileID.HasValue)
{
SetRequestFileID(request, fileID.Value);
}
SMB2Command response = ProcessSMB2Command(request, ref state);
if (response != null)
{
UpdateSMB2Header(response, request, state);
responseChain.Add(response);
if (!request.Header.IsRelatedOperations)
{
fileID = GetResponseFileID(response);
}
}
}
if (responseChain.Count > 0)
{
EnqueueResponseChain(state, responseChain);
}
}
/// <summary>
/// May return null
/// </summary>
private SMB2Command ProcessSMB2Command(SMB2Command command, ref ConnectionState state)
{
if (state.Dialect == SMBDialect.NotSet)
{
if (command is NegotiateRequest)
{
NegotiateRequest request = (NegotiateRequest)command;
SMB2Command response = NegotiateHelper.GetNegotiateResponse(request, m_securityProvider, state, m_serverGuid, m_serverStartTime);
if (state.Dialect != SMBDialect.NotSet)
{
state = new SMB2ConnectionState(state);
m_connectionManager.AddConnection(state);
}
return response;
}
else
{
// [MS-SMB2] If the request being received is not an SMB2 NEGOTIATE Request [..]
// and Connection.NegotiateDialect is 0xFFFF or 0x02FF, the server MUST
// disconnect the connection.
state.LogToServer(Severity.Debug, "Invalid Connection State for command {0}", command.CommandName.ToString());
state.ClientSocket.Close();
return null;
}
}
else if (command is NegotiateRequest)
{
// [MS-SMB2] If Connection.NegotiateDialect is 0x0202, 0x0210, 0x0300, 0x0302, or 0x0311,
// the server MUST disconnect the connection.
state.LogToServer(Severity.Debug, "Rejecting NegotiateRequest. NegotiateDialect is already set");
state.ClientSocket.Close();
return null;
}
else
{
return ProcessSMB2Command(command, (SMB2ConnectionState)state);
}
}
private SMB2Command ProcessSMB2Command(SMB2Command command, SMB2ConnectionState state)
{
if (command is SessionSetupRequest)
{
return SessionSetupHelper.GetSessionSetupResponse((SessionSetupRequest)command, m_securityProvider, state);
}
else if (command is EchoRequest)
{
return new EchoResponse();
}
else
{
SMB2Session session = state.GetSession(command.Header.SessionID);
if (session == null)
{
return new ErrorResponse(command.CommandName, NTStatus.STATUS_USER_SESSION_DELETED);
}
if (command is TreeConnectRequest)
{
return TreeConnectHelper.GetTreeConnectResponse((TreeConnectRequest)command, state, m_services, m_shares);
}
else if (command is LogoffRequest)
{
state.LogToServer(Severity.Information, "Logoff: User '{0}' logged off. (SessionID: {1})", session.UserName, command.Header.SessionID);
m_securityProvider.DeleteSecurityContext(ref session.SecurityContext.AuthenticationContext);
state.RemoveSession(command.Header.SessionID);
return new LogoffResponse();
}
else if (command.Header.IsAsync)
{
// TreeID will not be present in an ASYNC header
if (command is CancelRequest)
{
return CancelHelper.GetCancelResponse((CancelRequest)command, state);
}
}
else
{
ISMBShare share = session.GetConnectedTree(command.Header.TreeID);
if (share == null)
{
state.LogToServer(Severity.Verbose, "{0} failed. Invalid TreeID (SessionID: {1}, TreeID: {2}).", command.CommandName, command.Header.SessionID, command.Header.TreeID);
return new ErrorResponse(command.CommandName, NTStatus.STATUS_NETWORK_NAME_DELETED);
}
if (command is TreeDisconnectRequest)
{
return TreeConnectHelper.GetTreeDisconnectResponse((TreeDisconnectRequest)command, share, state);
}
else if (command is CreateRequest)
{
return CreateHelper.GetCreateResponse((CreateRequest)command, share, state);
}
else if (command is QueryInfoRequest)
{
return QueryInfoHelper.GetQueryInfoResponse((QueryInfoRequest)command, share, state);
}
else if (command is SetInfoRequest)
{
return SetInfoHelper.GetSetInfoResponse((SetInfoRequest)command, share, state);
}
else if (command is QueryDirectoryRequest)
{
return QueryDirectoryHelper.GetQueryDirectoryResponse((QueryDirectoryRequest)command, share, state);
}
else if (command is ReadRequest)
{
return ReadWriteResponseHelper.GetReadResponse((ReadRequest)command, share, state);
}
else if (command is WriteRequest)
{
return ReadWriteResponseHelper.GetWriteResponse((WriteRequest)command, share, state);
}
else if (command is LockRequest)
{
return LockHelper.GetLockResponse((LockRequest)command, share, state);
}
else if (command is FlushRequest)
{
return ReadWriteResponseHelper.GetFlushResponse((FlushRequest)command, share, state);
}
else if (command is CloseRequest)
{
return CloseHelper.GetCloseResponse((CloseRequest)command, share, state);
}
else if (command is IOCtlRequest)
{
return IOCtlHelper.GetIOCtlResponse((IOCtlRequest)command, share, state);
}
else if (command is CancelRequest)
{
return CancelHelper.GetCancelResponse((CancelRequest)command, state);
}
else if (command is ChangeNotifyRequest)
{
return ChangeNotifyHelper.GetChangeNotifyInterimResponse((ChangeNotifyRequest)command, share, state);
}
}
}
return new ErrorResponse(command.CommandName, NTStatus.STATUS_NOT_SUPPORTED);
}
internal static void EnqueueResponse(ConnectionState state, SMB2Command response)
{
List<SMB2Command> responseChain = new List<SMB2Command>();
responseChain.Add(response);
EnqueueResponseChain(state, responseChain);
}
private static void EnqueueResponseChain(ConnectionState state, List<SMB2Command> responseChain)
{
byte[] sessionKey = null;
if (state is SMB2ConnectionState)
{
// Note: multiple sessions MAY be multiplexed on the same connection, so theoretically
// we could have compounding unrelated requests from different sessions.
// In practice however this is not a real problem.
ulong sessionID = responseChain[0].Header.SessionID;
if (sessionID != 0)
{
SMB2Session session = ((SMB2ConnectionState)state).GetSession(sessionID);
if (session != null)
{
sessionKey = session.SessionKey;
}
}
}
SessionMessagePacket packet = new SessionMessagePacket();
packet.Trailer = SMB2Command.GetCommandChainBytes(responseChain, sessionKey);
state.SendQueue.Enqueue(packet);
state.LogToServer(Severity.Verbose, "SMB2 response chain queued: Response count: {0}, First response: {1}, Packet length: {2}", responseChain.Count, responseChain[0].CommandName.ToString(), packet.Length);
}
private static void UpdateSMB2Header(SMB2Command response, SMB2Command request, ConnectionState state)
{
response.Header.MessageID = request.Header.MessageID;
response.Header.CreditCharge = request.Header.CreditCharge;
response.Header.Credits = Math.Max((ushort)1, request.Header.Credits);
response.Header.IsRelatedOperations = request.Header.IsRelatedOperations;
response.Header.Reserved = request.Header.Reserved;
if (response.Header.SessionID == 0)
{
response.Header.SessionID = request.Header.SessionID;
}
if (response.Header.TreeID == 0)
{
response.Header.TreeID = request.Header.TreeID;
}
bool signingRequired = false;
if (state is SMB2ConnectionState)
{
SMB2Session session = ((SMB2ConnectionState)state).GetSession(response.Header.SessionID);
if (session != null && session.SigningRequired)
{
signingRequired = true;
}
}
// [MS-SMB2] The server SHOULD sign the message [..] if the request was signed by the client,
// and the response is not an interim response to an asynchronously processed request.
bool isInterimResponse = (response.Header.IsAsync && response.Header.Status == NTStatus.STATUS_PENDING);
response.Header.IsSigned = (request.Header.IsSigned || signingRequired) && !isInterimResponse;
}
private static void SetRequestFileID(SMB2Command command, FileID fileID)
{
if (command is ChangeNotifyRequest)
{
((ChangeNotifyRequest)command).FileId = fileID;
}
else if (command is CloseRequest)
{
((CloseRequest)command).FileId = fileID;
}
else if (command is FlushRequest)
{
((FlushRequest)command).FileId = fileID;
}
else if (command is IOCtlRequest)
{
((IOCtlRequest)command).FileId = fileID;
}
else if (command is LockRequest)
{
((LockRequest)command).FileId = fileID;
}
else if (command is QueryDirectoryRequest)
{
((QueryDirectoryRequest)command).FileId = fileID;
}
else if (command is QueryInfoRequest)
{
((QueryInfoRequest)command).FileId = fileID;
}
else if (command is ReadRequest)
{
((ReadRequest)command).FileId = fileID;
}
else if (command is SetInfoRequest)
{
((SetInfoRequest)command).FileId = fileID;
}
else if (command is WriteRequest)
{
((WriteRequest)command).FileId = fileID;
}
}
private static FileID? GetResponseFileID(SMB2Command command)
{
if (command is CreateResponse)
{
return ((CreateResponse)command).FileId;
}
else if (command is IOCtlResponse)
{
return ((IOCtlResponse)command).FileId;
}
return null;
}
}
}