Пример #1
0
        protected virtual void ProcessBackendResponses_Ver_3( NpgsqlConnector context )
        {
            NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ProcessBackendResponses");

            Stream 	stream = context.Stream;
            NpgsqlMediator mediator = context.Mediator;

            // Often used buffers
            Byte[] inputBuffer = new Byte[ 4 ];
            String Str;

            Boolean readyForQuery = false;

            byte[] asciiRowBytes = new byte[300];
            char[] asciiRowChars = new char[300];

            while (!readyForQuery)
            {
                // Check the first Byte of response.
                Int32 message = stream.ReadByte();
                switch ( message )
                {
                case NpgsqlMessageTypes_Ver_3.ErrorResponse :

                    {
                        NpgsqlError error = new NpgsqlError(context.BackendProtocolVersion);
                        error.ReadFromStream(stream, context.Encoding);
                        error.ErrorSql = mediator.SqlSent;

                        mediator.Errors.Add(error);

                        NpgsqlEventLog.LogMsg(resman, "Log_ErrorResponse", LogLevel.Debug, error.Message);
                    }

                    // Return imediately if it is in the startup state or connected state as
                    // there is no more messages to consume.
                    // Possible error in the NpgsqlStartupState:
                    //		Invalid password.
                    // Possible error in the NpgsqlConnectedState:
                    //		No pg_hba.conf configured.

                    if (! mediator.RequireReadyForQuery)
                    {
                        return;
                    }

                    break;


                case NpgsqlMessageTypes_Ver_3.AuthenticationRequest :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "AuthenticationRequest");

                    // Eat length
                    PGUtil.ReadInt32(stream, inputBuffer);

                    {
                        Int32 authType = PGUtil.ReadInt32(stream, inputBuffer);

                        if ( authType == NpgsqlMessageTypes_Ver_3.AuthenticationOk )
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationOK", LogLevel.Debug);

                            break;
                        }

                        if ( authType == NpgsqlMessageTypes_Ver_3.AuthenticationClearTextPassword )
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationClearTextRequest", LogLevel.Debug);

                            // Send the PasswordPacket.

                            ChangeState( context, NpgsqlStartupState.Instance );
                            context.Authenticate(context.Password);

                            break;
                        }


                        if ( authType == NpgsqlMessageTypes_Ver_3.AuthenticationMD5Password )
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationMD5Request", LogLevel.Debug);
                            // Now do the "MD5-Thing"
                            // for this the Password has to be:
                            // 1. md5-hashed with the username as salt
                            // 2. md5-hashed again with the salt we get from the backend


                            MD5 md5 = MD5.Create();


                            // 1.
                            byte[] passwd = context.Encoding.GetBytes(context.Password);
                            byte[] saltUserName = context.Encoding.GetBytes(context.UserName);

                            byte[] crypt_buf = new byte[passwd.Length + saltUserName.Length];

                            passwd.CopyTo(crypt_buf, 0);
                            saltUserName.CopyTo(crypt_buf, passwd.Length);



                            StringBuilder sb = new StringBuilder ();
                            byte[] hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            sb.Append (b.ToString ("x2"));


                            String prehash = sb.ToString();

                            byte[] prehashbytes = context.Encoding.GetBytes(prehash);



                            stream.Read(inputBuffer, 0, 4);
                            // Send the PasswordPacket.
                            ChangeState( context, NpgsqlStartupState.Instance );


                            // 2.

                            crypt_buf = new byte[prehashbytes.Length + 4];
                            prehashbytes.CopyTo(crypt_buf, 0);
                            inputBuffer.CopyTo(crypt_buf, prehashbytes.Length);

                            sb = new StringBuilder ("md5"); // This is needed as the backend expects md5 result starts with "md5"
                            hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            sb.Append (b.ToString ("x2"));

                            context.Authenticate(sb.ToString ());

                            break;
                        }

                        // Only AuthenticationClearTextPassword and AuthenticationMD5Password supported for now.
                        mediator.Errors.Add(new NpgsqlError(context.BackendProtocolVersion, String.Format(resman.GetString("Exception_AuthenticationMethodNotSupported"), authType)));
                    }

                    return;

                case NpgsqlMessageTypes_Ver_3.RowDescription:
                    // This is the RowDescription message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "RowDescription");
                    {
                        NpgsqlRowDescription rd = new NpgsqlRowDescription(context.BackendProtocolVersion);
                        rd.ReadFromStream(stream, context.Encoding, context.OidToNameMapping);

                        mediator.AddRowDescription(rd);
                    }

                    // Now wait for the AsciiRow messages.
                    break;
                case NpgsqlMessageTypes_Ver_3.ParameterDescription:
                    
                    // Do nothing,for instance,  just read...
                    int lenght = PGUtil.ReadInt32(stream, inputBuffer);
                    int nb_param = PGUtil.ReadInt16(stream, inputBuffer);
                    for (int i=0; i < nb_param; i++)
                    {
                        int typeoid = PGUtil.ReadInt32(stream, inputBuffer);
                    }
                    
                    break;

                case NpgsqlMessageTypes_Ver_3.DataRow:
                    // This is the AsciiRow message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "DataRow");
                    {
                        NpgsqlAsciiRow asciiRow = new NpgsqlAsciiRow(context.Mediator.LastRowDescription, context.BackendProtocolVersion, asciiRowBytes, asciiRowChars);
                        asciiRow.ReadFromStream(stream, context.Encoding);

                        // Add this row to the rows array.
                        mediator.AddAsciiRow(asciiRow);
                    }

                    // Now wait for CompletedResponse message.
                    break;

                case NpgsqlMessageTypes_Ver_3.ReadyForQuery :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ReadyForQuery");

                    // Possible status bytes returned:
                    //   I = Idle (no transaction active).
                    //   T = In transaction, ready for more.
                    //   E = Error in transaction, queries will fail until transaction aborted.
                    // Just eat the status byte, we have no use for it at this time.
                    PGUtil.ReadInt32(stream, inputBuffer);
                    PGUtil.ReadString(stream, context.Encoding, 1);

                    readyForQuery = true;
                    ChangeState( context, NpgsqlReadyState.Instance );

                    break;

                case NpgsqlMessageTypes_Ver_3.BackendKeyData :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BackendKeyData");
                    // BackendKeyData message.
                    NpgsqlBackEndKeyData backend_keydata = new NpgsqlBackEndKeyData(context.BackendProtocolVersion);
                    backend_keydata.ReadFromStream(stream);
                    mediator.SetBackendKeydata(backend_keydata);


                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_3.NoticeResponse :

                    // Notices and errors are identical except that we
                    // just throw notices away completely ignored.
                    {
                        NpgsqlError notice = new NpgsqlError(context.BackendProtocolVersion);
                        notice.ReadFromStream(stream, context.Encoding);

                        mediator.Notices.Add(notice);

                        NpgsqlEventLog.LogMsg(resman, "Log_NoticeResponse", LogLevel.Debug, notice.Message);
                    }

                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_3.CompletedResponse :
                    // This is the CompletedResponse message.
                    // Get the string returned.

                    PGUtil.ReadInt32(stream, inputBuffer);
                    Str = PGUtil.ReadString(stream, context.Encoding);

                    NpgsqlEventLog.LogMsg(resman, "Log_CompletedResponse", LogLevel.Debug, Str);

                    // Add result from the processing.
                    mediator.AddCompletedResponse(Str);

                    break;

                case NpgsqlMessageTypes_Ver_3.ParseComplete :
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ParseComplete");
                    // Just read up the message length.
                    PGUtil.ReadInt32(stream, inputBuffer);
                    readyForQuery = true;
                    break;

                case NpgsqlMessageTypes_Ver_3.BindComplete :
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BindComplete");
                    // Just read up the message length.
                    PGUtil.ReadInt32(stream, inputBuffer);
                    readyForQuery = true;
                    break;

                case NpgsqlMessageTypes_Ver_3.EmptyQueryResponse :
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "EmptyQueryResponse");
                    PGUtil.ReadInt32(stream, inputBuffer);
                    break;

                case NpgsqlMessageTypes_Ver_3.NotificationResponse  :
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "NotificationResponse");

                    // Eat the length
                    PGUtil.ReadInt32(stream, inputBuffer);
                    {
                        // Process ID sending notification
                        Int32 PID = PGUtil.ReadInt32(stream, inputBuffer);
                        // Notification string
                        String notificationResponse = PGUtil.ReadString( stream, context.Encoding );
                        // Additional info, currently not implemented by PG (empty string always), eat it
                        PGUtil.ReadString( stream, context.Encoding );
                        mediator.AddNotification(new NpgsqlNotificationEventArgs(PID, notificationResponse));
                    }
                    
                    if (context.IsNotificationThreadRunning)
                        readyForQuery = true;

                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_3.ParameterStatus :
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ParameterStatus");
                    NpgsqlParameterStatus parameterStatus = new NpgsqlParameterStatus();
                    parameterStatus.ReadFromStream(stream, context.Encoding);

                    NpgsqlEventLog.LogMsg(resman, "Log_ParameterStatus", LogLevel.Debug, parameterStatus.Parameter, parameterStatus.ParameterValue);

                    mediator.AddParameterStatus(parameterStatus.Parameter, parameterStatus);

                    if (parameterStatus.Parameter == "server_version")
                    {
                        // Add this one under our own name so that if the parameter name
                        // changes in a future backend version, we can handle it here in the
                        // protocol handler and leave everybody else put of it.
                        mediator.AddParameterStatus("__npgsql_server_version", parameterStatus);
                        //                        context.ServerVersionString = parameterStatus.ParameterValue;
                    }

                    break;
                case NpgsqlMessageTypes_Ver_3.NoData :
                    // This nodata message may be generated by prepare commands issued with queries which doesn't return rows
                    // for example insert, update or delete.
                    // Just eat the message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ParameterStatus");
                    PGUtil.ReadInt32(stream, inputBuffer);
                    break;


                case -1:
		    // Connection broken. Mono returns -1 instead of throw an exception as ms.net does.
		    throw new IOException();

                default :
                    // This could mean a number of things
                    //   We've gotten out of sync with the backend?
                    //   We need to implement this type?
                    //   Backend has gone insane?
                    // FIXME
                    // what exception should we really throw here?
                    throw new NotSupportedException(String.Format("Backend sent unrecognized response type: {0}", (Char)message));

                }
            }
        }
Пример #2
0
        protected virtual void ProcessBackendResponses_Ver_2( NpgsqlConnector context )
        {
            NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ProcessBackendResponses");

            Stream 	stream = context.Stream;
            NpgsqlMediator mediator = context.Mediator;

            // Often used buffer
            Byte[] inputBuffer = new Byte[ 4 ];

            Boolean readyForQuery = false;

            byte[] asciiRowBytes = new byte[300];
            char[] asciiRowChars = new char[300];

            while (!readyForQuery)
            {
                // Check the first Byte of response.
                switch ( stream.ReadByte() )
                {
                case NpgsqlMessageTypes_Ver_2.ErrorResponse :

                    {
                        NpgsqlError error = new NpgsqlError(context.BackendProtocolVersion);
                        error.ReadFromStream(stream, context.Encoding);
                        error.ErrorSql = mediator.SqlSent;

                        mediator.Errors.Add(error);

                        NpgsqlEventLog.LogMsg(resman, "Log_ErrorResponse", LogLevel.Debug, error.Message);
                    }

                    // Return imediately if it is in the startup state or connected state as
                    // there is no more messages to consume.
                    // Possible error in the NpgsqlStartupState:
                    //		Invalid password.
                    // Possible error in the NpgsqlConnectedState:
                    //		No pg_hba.conf configured.

                    if (! mediator.RequireReadyForQuery)
                    {
                        return;
                    }

                    break;


                case NpgsqlMessageTypes_Ver_2.AuthenticationRequest :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "AuthenticationRequest");

                    {
                        Int32 authType = PGUtil.ReadInt32(stream, inputBuffer);

                        if ( authType == NpgsqlMessageTypes_Ver_2.AuthenticationOk )
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationOK", LogLevel.Debug);

                            break;
                        }

                        if ( authType == NpgsqlMessageTypes_Ver_2.AuthenticationClearTextPassword )
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationClearTextRequest", LogLevel.Debug);

                            // Send the PasswordPacket.

                            ChangeState( context, NpgsqlStartupState.Instance );
                            context.Authenticate(context.Password);

                            break;
                        }


                        if ( authType == NpgsqlMessageTypes_Ver_2.AuthenticationMD5Password )
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationMD5Request", LogLevel.Debug);
                            // Now do the "MD5-Thing"
                            // for this the Password has to be:
                            // 1. md5-hashed with the username as salt
                            // 2. md5-hashed again with the salt we get from the backend


                            MD5 md5 = MD5.Create();


                            // 1.
                            byte[] passwd = context.Encoding.GetBytes(context.Password);
                            byte[] saltUserName = context.Encoding.GetBytes(context.UserName);

                            byte[] crypt_buf = new byte[passwd.Length + saltUserName.Length];

                            passwd.CopyTo(crypt_buf, 0);
                            saltUserName.CopyTo(crypt_buf, passwd.Length);



                            StringBuilder sb = new StringBuilder ();
                            byte[] hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            sb.Append (b.ToString ("x2"));


                            String prehash = sb.ToString();

                            byte[] prehashbytes = context.Encoding.GetBytes(prehash);



                            byte[] saltServer = new byte[4];
                            stream.Read(saltServer, 0, 4);
                            // Send the PasswordPacket.
                            ChangeState( context, NpgsqlStartupState.Instance );


                            // 2.

                            crypt_buf = new byte[prehashbytes.Length + saltServer.Length];
                            prehashbytes.CopyTo(crypt_buf, 0);
                            saltServer.CopyTo(crypt_buf, prehashbytes.Length);

                            sb = new StringBuilder ("md5"); // This is needed as the backend expects md5 result starts with "md5"
                            hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            sb.Append (b.ToString ("x2"));

                            context.Authenticate(sb.ToString ());

                            break;
                        }

                        // Only AuthenticationClearTextPassword and AuthenticationMD5Password supported for now.

                        mediator.Errors.Add(new NpgsqlError(context.BackendProtocolVersion, String.Format(resman.GetString("Exception_AuthenticationMethodNotSupported"), authType)));
                    }

                    return;

                case NpgsqlMessageTypes_Ver_2.RowDescription:
                    // This is the RowDescription message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "RowDescription");

                    {
                        NpgsqlRowDescription rd = new NpgsqlRowDescription(context.BackendProtocolVersion);
                        rd.ReadFromStream(stream, context.Encoding, context.OidToNameMapping);

                        // Initialize the array list which will contain the data from this rowdescription.
                        mediator.AddRowDescription(rd);
                    }

                    // Now wait for the AsciiRow messages.
                    break;

                case NpgsqlMessageTypes_Ver_2.AsciiRow:
                    // This is the AsciiRow message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "AsciiRow");

                    {
                        NpgsqlAsciiRow asciiRow = new NpgsqlAsciiRow(context.Mediator.LastRowDescription, context.BackendProtocolVersion, asciiRowBytes, asciiRowChars);
                        asciiRow.ReadFromStream(stream, context.Encoding);

                        // Add this row to the rows array.
                        mediator.AddAsciiRow(asciiRow);
                    }

                    // Now wait for CompletedResponse message.
                    break;

                case NpgsqlMessageTypes_Ver_2.BinaryRow:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BinaryRow");

                    {
                        NpgsqlBinaryRow binaryRow = new NpgsqlBinaryRow(context.Mediator.LastRowDescription);
                        binaryRow.ReadFromStream(stream, context.Encoding);

                        mediator.AddBinaryRow(binaryRow);
                    }

                    break;

                case NpgsqlMessageTypes_Ver_2.ReadyForQuery :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ReadyForQuery");
                    readyForQuery = true;
                    ChangeState( context, NpgsqlReadyState.Instance );
                    break;

                case NpgsqlMessageTypes_Ver_2.BackendKeyData :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BackendKeyData");
                    // BackendKeyData message.
                    NpgsqlBackEndKeyData backend_keydata = new NpgsqlBackEndKeyData(context.BackendProtocolVersion);
                    backend_keydata.ReadFromStream(stream);
                    mediator.SetBackendKeydata(backend_keydata);


                    // Wait for ReadForQuery message
                    break;
                    ;

                case NpgsqlMessageTypes_Ver_2.NoticeResponse :

                    {
                        NpgsqlError notice = new NpgsqlError(context.BackendProtocolVersion);
                        notice.ReadFromStream(stream, context.Encoding);

                        mediator.Notices.Add(notice);

                        NpgsqlEventLog.LogMsg(resman, "Log_NoticeResponse", LogLevel.Debug, notice.Message);
                    }

                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_2.CompletedResponse :
                    // This is the CompletedResponse message.
                    // Get the string returned.


                    String result = PGUtil.ReadString(stream, context.Encoding);

                    NpgsqlEventLog.LogMsg(resman, "Log_CompletedResponse", LogLevel.Debug, result);
                    // Add result from the processing.

                    mediator.AddCompletedResponse(result);

                    // Now wait for ReadyForQuery message.
                    break;

                case NpgsqlMessageTypes_Ver_2.CursorResponse :
                    // This is the cursor response message.
                    // It is followed by a C NULL terminated string with the name of
                    // the cursor in a FETCH case or 'blank' otherwise.
                    // In this case it should be always 'blank'.
                    // [FIXME] Get another name for this function.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "CursorResponse");

                    String cursorName = PGUtil.ReadString(stream, context.Encoding);
                    // Continue waiting for ReadyForQuery message.
                    break;

                case NpgsqlMessageTypes_Ver_2.EmptyQueryResponse :
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "EmptyQueryResponse");
                    PGUtil.ReadString(stream, context.Encoding);
                    break;

                case NpgsqlMessageTypes_Ver_2.NotificationResponse  :

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "NotificationResponse");

                    Int32 PID = PGUtil.ReadInt32(stream, inputBuffer);
                    String notificationResponse = PGUtil.ReadString( stream, context.Encoding );
                    mediator.AddNotification(new NpgsqlNotificationEventArgs(PID, notificationResponse));
                    
                    if (context.IsNotificationThreadRunning)
                        readyForQuery = true;

                    // Wait for ReadForQuery message
                    break;

                case -1:
                    // Connection broken. Mono returns -1 instead of throw an exception as ms.net does.
                    throw new IOException();

                default :
                    // This could mean a number of things
                    //   We've gotten out of sync with the backend?
                    //   We need to implement this type?
                    //   Backend has gone insane?
                    // FIXME
                    // what exception should we really throw here?
                    throw new NotSupportedException("Backend sent unrecognized response type");

                }
            }
        }
Пример #3
0
        protected virtual void ProcessBackendResponses_Ver_3(NpgsqlConnector context)
        {
            NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ProcessBackendResponses");

            Stream         stream   = context.Stream;
            NpgsqlMediator mediator = context.Mediator;

            // Often used buffers
            Byte[] inputBuffer = new Byte[4];
            String Str;

            Boolean readyForQuery = false;

            byte[] asciiRowBytes = new byte[300];
            char[] asciiRowChars = new char[300];

            while (!readyForQuery)
            {
                // Check the first Byte of response.
                Int32 message = stream.ReadByte();
                switch (message)
                {
                case NpgsqlMessageTypes_Ver_3.ErrorResponse:

                {
                    NpgsqlError error = new NpgsqlError(context.BackendProtocolVersion);
                    error.ReadFromStream(stream, context.Encoding);
                    error.ErrorSql = mediator.SqlSent;

                    mediator.Errors.Add(error);

                    NpgsqlEventLog.LogMsg(resman, "Log_ErrorResponse", LogLevel.Debug, error.Message);
                }

                    // Return imediately if it is in the startup state or connected state as
                    // there is no more messages to consume.
                    // Possible error in the NpgsqlStartupState:
                    //		Invalid password.
                    // Possible error in the NpgsqlConnectedState:
                    //		No pg_hba.conf configured.

                    if (!mediator.RequireReadyForQuery)
                    {
                        return;
                    }

                    break;


                case NpgsqlMessageTypes_Ver_3.AuthenticationRequest:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "AuthenticationRequest");

                    // Eat length
                    PGUtil.ReadInt32(stream, inputBuffer);

                    {
                        Int32 authType = PGUtil.ReadInt32(stream, inputBuffer);

                        if (authType == NpgsqlMessageTypes_Ver_3.AuthenticationOk)
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationOK", LogLevel.Debug);

                            break;
                        }

                        if (authType == NpgsqlMessageTypes_Ver_3.AuthenticationClearTextPassword)
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationClearTextRequest", LogLevel.Debug);

                            // Send the PasswordPacket.

                            ChangeState(context, NpgsqlStartupState.Instance);
                            context.Authenticate(context.Password);

                            break;
                        }


                        if (authType == NpgsqlMessageTypes_Ver_3.AuthenticationMD5Password)
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationMD5Request", LogLevel.Debug);
                            // Now do the "MD5-Thing"
                            // for this the Password has to be:
                            // 1. md5-hashed with the username as salt
                            // 2. md5-hashed again with the salt we get from the backend


                            MD5 md5 = MD5.Create();


                            // 1.
                            byte[] passwd       = context.Encoding.GetBytes(context.Password);
                            byte[] saltUserName = context.Encoding.GetBytes(context.UserName);

                            byte[] crypt_buf = new byte[passwd.Length + saltUserName.Length];

                            passwd.CopyTo(crypt_buf, 0);
                            saltUserName.CopyTo(crypt_buf, passwd.Length);



                            StringBuilder sb         = new StringBuilder();
                            byte[]        hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            {
                                sb.Append(b.ToString("x2"));
                            }


                            String prehash = sb.ToString();

                            byte[] prehashbytes = context.Encoding.GetBytes(prehash);



                            stream.Read(inputBuffer, 0, 4);
                            // Send the PasswordPacket.
                            ChangeState(context, NpgsqlStartupState.Instance);


                            // 2.

                            crypt_buf = new byte[prehashbytes.Length + 4];
                            prehashbytes.CopyTo(crypt_buf, 0);
                            inputBuffer.CopyTo(crypt_buf, prehashbytes.Length);

                            sb         = new StringBuilder("md5"); // This is needed as the backend expects md5 result starts with "md5"
                            hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            {
                                sb.Append(b.ToString("x2"));
                            }

                            context.Authenticate(sb.ToString());

                            break;
                        }

                        // Only AuthenticationClearTextPassword and AuthenticationMD5Password supported for now.
                        mediator.Errors.Add(new NpgsqlError(context.BackendProtocolVersion, String.Format(resman.GetString("Exception_AuthenticationMethodNotSupported"), authType)));
                    }

                    return;

                case NpgsqlMessageTypes_Ver_3.RowDescription:
                    // This is the RowDescription message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "RowDescription");
                    {
                        NpgsqlRowDescription rd = new NpgsqlRowDescription(context.BackendProtocolVersion);
                        rd.ReadFromStream(stream, context.Encoding, context.OidToNameMapping);

                        mediator.AddRowDescription(rd);
                    }

                    // Now wait for the AsciiRow messages.
                    break;

                case NpgsqlMessageTypes_Ver_3.ParameterDescription:

                    // Do nothing,for instance,  just read...
                    int lenght   = PGUtil.ReadInt32(stream, inputBuffer);
                    int nb_param = PGUtil.ReadInt16(stream, inputBuffer);
                    for (int i = 0; i < nb_param; i++)
                    {
                        int typeoid = PGUtil.ReadInt32(stream, inputBuffer);
                    }

                    break;

                case NpgsqlMessageTypes_Ver_3.DataRow:
                    // This is the AsciiRow message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "DataRow");
                    {
                        NpgsqlAsciiRow asciiRow = new NpgsqlAsciiRow(context.Mediator.LastRowDescription, context.BackendProtocolVersion, asciiRowBytes, asciiRowChars);
                        asciiRow.ReadFromStream(stream, context.Encoding);

                        // Add this row to the rows array.
                        mediator.AddAsciiRow(asciiRow);
                    }

                    // Now wait for CompletedResponse message.
                    break;

                case NpgsqlMessageTypes_Ver_3.ReadyForQuery:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ReadyForQuery");

                    // Possible status bytes returned:
                    //   I = Idle (no transaction active).
                    //   T = In transaction, ready for more.
                    //   E = Error in transaction, queries will fail until transaction aborted.
                    // Just eat the status byte, we have no use for it at this time.
                    PGUtil.ReadInt32(stream, inputBuffer);
                    PGUtil.ReadString(stream, context.Encoding, 1);

                    readyForQuery = true;
                    ChangeState(context, NpgsqlReadyState.Instance);

                    break;

                case NpgsqlMessageTypes_Ver_3.BackendKeyData:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BackendKeyData");
                    // BackendKeyData message.
                    NpgsqlBackEndKeyData backend_keydata = new NpgsqlBackEndKeyData(context.BackendProtocolVersion);
                    backend_keydata.ReadFromStream(stream);
                    mediator.SetBackendKeydata(backend_keydata);


                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_3.NoticeResponse:

                    // Notices and errors are identical except that we
                    // just throw notices away completely ignored.
                {
                    NpgsqlError notice = new NpgsqlError(context.BackendProtocolVersion);
                    notice.ReadFromStream(stream, context.Encoding);

                    mediator.Notices.Add(notice);

                    NpgsqlEventLog.LogMsg(resman, "Log_NoticeResponse", LogLevel.Debug, notice.Message);
                }

                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_3.CompletedResponse:
                    // This is the CompletedResponse message.
                    // Get the string returned.

                    PGUtil.ReadInt32(stream, inputBuffer);
                    Str = PGUtil.ReadString(stream, context.Encoding);

                    NpgsqlEventLog.LogMsg(resman, "Log_CompletedResponse", LogLevel.Debug, Str);

                    // Add result from the processing.
                    mediator.AddCompletedResponse(Str);

                    break;

                case NpgsqlMessageTypes_Ver_3.ParseComplete:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ParseComplete");
                    // Just read up the message length.
                    PGUtil.ReadInt32(stream, inputBuffer);
                    readyForQuery = true;
                    break;

                case NpgsqlMessageTypes_Ver_3.BindComplete:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BindComplete");
                    // Just read up the message length.
                    PGUtil.ReadInt32(stream, inputBuffer);
                    readyForQuery = true;
                    break;

                case NpgsqlMessageTypes_Ver_3.EmptyQueryResponse:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "EmptyQueryResponse");
                    PGUtil.ReadInt32(stream, inputBuffer);
                    break;

                case NpgsqlMessageTypes_Ver_3.NotificationResponse:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "NotificationResponse");

                    // Eat the length
                    PGUtil.ReadInt32(stream, inputBuffer);
                    {
                        // Process ID sending notification
                        Int32 PID = PGUtil.ReadInt32(stream, inputBuffer);
                        // Notification string
                        String notificationResponse = PGUtil.ReadString(stream, context.Encoding);
                        // Additional info, currently not implemented by PG (empty string always), eat it
                        PGUtil.ReadString(stream, context.Encoding);
                        mediator.AddNotification(new NpgsqlNotificationEventArgs(PID, notificationResponse));
                    }

                    if (context.IsNotificationThreadRunning)
                    {
                        readyForQuery = true;
                    }

                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_3.ParameterStatus:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ParameterStatus");
                    NpgsqlParameterStatus parameterStatus = new NpgsqlParameterStatus();
                    parameterStatus.ReadFromStream(stream, context.Encoding);

                    NpgsqlEventLog.LogMsg(resman, "Log_ParameterStatus", LogLevel.Debug, parameterStatus.Parameter, parameterStatus.ParameterValue);

                    mediator.AddParameterStatus(parameterStatus.Parameter, parameterStatus);

                    if (parameterStatus.Parameter == "server_version")
                    {
                        // Add this one under our own name so that if the parameter name
                        // changes in a future backend version, we can handle it here in the
                        // protocol handler and leave everybody else put of it.
                        mediator.AddParameterStatus("__npgsql_server_version", parameterStatus);
                        //                        context.ServerVersionString = parameterStatus.ParameterValue;
                    }

                    break;

                case NpgsqlMessageTypes_Ver_3.NoData:
                    // This nodata message may be generated by prepare commands issued with queries which doesn't return rows
                    // for example insert, update or delete.
                    // Just eat the message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ParameterStatus");
                    PGUtil.ReadInt32(stream, inputBuffer);
                    break;


                case -1:
                    // Connection broken. Mono returns -1 instead of throw an exception as ms.net does.
                    throw new IOException();

                default:
                    // This could mean a number of things
                    //   We've gotten out of sync with the backend?
                    //   We need to implement this type?
                    //   Backend has gone insane?
                    // FIXME
                    // what exception should we really throw here?
                    throw new NotSupportedException(String.Format("Backend sent unrecognized response type: {0}", (Char)message));
                }
            }
        }
Пример #4
0
        protected virtual void ProcessBackendResponses_Ver_2(NpgsqlConnector context)
        {
            NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "ProcessBackendResponses");

            Stream         stream   = context.Stream;
            NpgsqlMediator mediator = context.Mediator;

            // Often used buffer
            Byte[] inputBuffer = new Byte[4];

            Boolean readyForQuery = false;

            byte[] asciiRowBytes = new byte[300];
            char[] asciiRowChars = new char[300];

            while (!readyForQuery)
            {
                // Check the first Byte of response.
                switch (stream.ReadByte())
                {
                case NpgsqlMessageTypes_Ver_2.ErrorResponse:

                {
                    NpgsqlError error = new NpgsqlError(context.BackendProtocolVersion);
                    error.ReadFromStream(stream, context.Encoding);
                    error.ErrorSql = mediator.SqlSent;

                    mediator.Errors.Add(error);

                    NpgsqlEventLog.LogMsg(resman, "Log_ErrorResponse", LogLevel.Debug, error.Message);
                }

                    // Return imediately if it is in the startup state or connected state as
                    // there is no more messages to consume.
                    // Possible error in the NpgsqlStartupState:
                    //		Invalid password.
                    // Possible error in the NpgsqlConnectedState:
                    //		No pg_hba.conf configured.

                    if (!mediator.RequireReadyForQuery)
                    {
                        return;
                    }

                    break;


                case NpgsqlMessageTypes_Ver_2.AuthenticationRequest:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "AuthenticationRequest");

                    {
                        Int32 authType = PGUtil.ReadInt32(stream, inputBuffer);

                        if (authType == NpgsqlMessageTypes_Ver_2.AuthenticationOk)
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationOK", LogLevel.Debug);

                            break;
                        }

                        if (authType == NpgsqlMessageTypes_Ver_2.AuthenticationClearTextPassword)
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationClearTextRequest", LogLevel.Debug);

                            // Send the PasswordPacket.

                            ChangeState(context, NpgsqlStartupState.Instance);
                            context.Authenticate(context.Password);

                            break;
                        }


                        if (authType == NpgsqlMessageTypes_Ver_2.AuthenticationMD5Password)
                        {
                            NpgsqlEventLog.LogMsg(resman, "Log_AuthenticationMD5Request", LogLevel.Debug);
                            // Now do the "MD5-Thing"
                            // for this the Password has to be:
                            // 1. md5-hashed with the username as salt
                            // 2. md5-hashed again with the salt we get from the backend


                            MD5 md5 = MD5.Create();


                            // 1.
                            byte[] passwd       = context.Encoding.GetBytes(context.Password);
                            byte[] saltUserName = context.Encoding.GetBytes(context.UserName);

                            byte[] crypt_buf = new byte[passwd.Length + saltUserName.Length];

                            passwd.CopyTo(crypt_buf, 0);
                            saltUserName.CopyTo(crypt_buf, passwd.Length);



                            StringBuilder sb         = new StringBuilder();
                            byte[]        hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            {
                                sb.Append(b.ToString("x2"));
                            }


                            String prehash = sb.ToString();

                            byte[] prehashbytes = context.Encoding.GetBytes(prehash);



                            byte[] saltServer = new byte[4];
                            stream.Read(saltServer, 0, 4);
                            // Send the PasswordPacket.
                            ChangeState(context, NpgsqlStartupState.Instance);


                            // 2.

                            crypt_buf = new byte[prehashbytes.Length + saltServer.Length];
                            prehashbytes.CopyTo(crypt_buf, 0);
                            saltServer.CopyTo(crypt_buf, prehashbytes.Length);

                            sb         = new StringBuilder("md5"); // This is needed as the backend expects md5 result starts with "md5"
                            hashResult = md5.ComputeHash(crypt_buf);
                            foreach (byte b in hashResult)
                            {
                                sb.Append(b.ToString("x2"));
                            }

                            context.Authenticate(sb.ToString());

                            break;
                        }

                        // Only AuthenticationClearTextPassword and AuthenticationMD5Password supported for now.

                        mediator.Errors.Add(new NpgsqlError(context.BackendProtocolVersion, String.Format(resman.GetString("Exception_AuthenticationMethodNotSupported"), authType)));
                    }

                    return;

                case NpgsqlMessageTypes_Ver_2.RowDescription:
                    // This is the RowDescription message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "RowDescription");

                    {
                        NpgsqlRowDescription rd = new NpgsqlRowDescription(context.BackendProtocolVersion);
                        rd.ReadFromStream(stream, context.Encoding, context.OidToNameMapping);

                        // Initialize the array list which will contain the data from this rowdescription.
                        mediator.AddRowDescription(rd);
                    }

                    // Now wait for the AsciiRow messages.
                    break;

                case NpgsqlMessageTypes_Ver_2.AsciiRow:
                    // This is the AsciiRow message.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "AsciiRow");

                    {
                        NpgsqlAsciiRow asciiRow = new NpgsqlAsciiRow(context.Mediator.LastRowDescription, context.BackendProtocolVersion, asciiRowBytes, asciiRowChars);
                        asciiRow.ReadFromStream(stream, context.Encoding);

                        // Add this row to the rows array.
                        mediator.AddAsciiRow(asciiRow);
                    }

                    // Now wait for CompletedResponse message.
                    break;

                case NpgsqlMessageTypes_Ver_2.BinaryRow:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BinaryRow");

                    {
                        NpgsqlBinaryRow binaryRow = new NpgsqlBinaryRow(context.Mediator.LastRowDescription);
                        binaryRow.ReadFromStream(stream, context.Encoding);

                        mediator.AddBinaryRow(binaryRow);
                    }

                    break;

                case NpgsqlMessageTypes_Ver_2.ReadyForQuery:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "ReadyForQuery");
                    readyForQuery = true;
                    ChangeState(context, NpgsqlReadyState.Instance);
                    break;

                case NpgsqlMessageTypes_Ver_2.BackendKeyData:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "BackendKeyData");
                    // BackendKeyData message.
                    NpgsqlBackEndKeyData backend_keydata = new NpgsqlBackEndKeyData(context.BackendProtocolVersion);
                    backend_keydata.ReadFromStream(stream);
                    mediator.SetBackendKeydata(backend_keydata);


                    // Wait for ReadForQuery message
                    break;
                    ;

                case NpgsqlMessageTypes_Ver_2.NoticeResponse:

                {
                    NpgsqlError notice = new NpgsqlError(context.BackendProtocolVersion);
                    notice.ReadFromStream(stream, context.Encoding);

                    mediator.Notices.Add(notice);

                    NpgsqlEventLog.LogMsg(resman, "Log_NoticeResponse", LogLevel.Debug, notice.Message);
                }

                    // Wait for ReadForQuery message
                    break;

                case NpgsqlMessageTypes_Ver_2.CompletedResponse:
                    // This is the CompletedResponse message.
                    // Get the string returned.


                    String result = PGUtil.ReadString(stream, context.Encoding);

                    NpgsqlEventLog.LogMsg(resman, "Log_CompletedResponse", LogLevel.Debug, result);
                    // Add result from the processing.

                    mediator.AddCompletedResponse(result);

                    // Now wait for ReadyForQuery message.
                    break;

                case NpgsqlMessageTypes_Ver_2.CursorResponse:
                    // This is the cursor response message.
                    // It is followed by a C NULL terminated string with the name of
                    // the cursor in a FETCH case or 'blank' otherwise.
                    // In this case it should be always 'blank'.
                    // [FIXME] Get another name for this function.
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "CursorResponse");

                    String cursorName = PGUtil.ReadString(stream, context.Encoding);
                    // Continue waiting for ReadyForQuery message.
                    break;

                case NpgsqlMessageTypes_Ver_2.EmptyQueryResponse:
                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "EmptyQueryResponse");
                    PGUtil.ReadString(stream, context.Encoding);
                    break;

                case NpgsqlMessageTypes_Ver_2.NotificationResponse:

                    NpgsqlEventLog.LogMsg(resman, "Log_ProtocolMessage", LogLevel.Debug, "NotificationResponse");

                    Int32  PID = PGUtil.ReadInt32(stream, inputBuffer);
                    String notificationResponse = PGUtil.ReadString(stream, context.Encoding);
                    mediator.AddNotification(new NpgsqlNotificationEventArgs(PID, notificationResponse));

                    if (context.IsNotificationThreadRunning)
                    {
                        readyForQuery = true;
                    }

                    // Wait for ReadForQuery message
                    break;

                case -1:
                    // Connection broken. Mono returns -1 instead of throw an exception as ms.net does.
                    throw new IOException();

                default:
                    // This could mean a number of things
                    //   We've gotten out of sync with the backend?
                    //   We need to implement this type?
                    //   Backend has gone insane?
                    // FIXME
                    // what exception should we really throw here?
                    throw new NotSupportedException("Backend sent unrecognized response type");
                }
            }
        }
Пример #5
0
        private Object FastpathV2(Int32 fnid, Boolean resulttype, FastpathArg[] args)
        {
            // added Oct 7 1998 to give us thread safety
            lock (stream)
            {
                // send the function call
                try
                {
                    // 70 is 'F' in ASCII. Note: don't use SendChar() here as it adds padding
                    // that confuses the backend. The 0 terminates the command line.
                    stream.WriteByte((Byte)70);
                    stream.WriteByte((Byte)0);

                    PGUtil.WriteInt32(stream,fnid);
                    PGUtil.WriteInt32(stream,args.Length);


                    for (Int32 i = 0;i < args.Length;i++)
                        args[i].Send(stream);

                    // This is needed, otherwise data can be lost
                    stream.Flush();

                }
                catch (IOException ioe)
                {
                    //Should be sending exception as second arg.
                    throw new Exception("postgresql.fp.send: "  + ioe.ToString());
                }

                // Now handle the result

                // Now loop, reading the results
                Object result = null; // our result
                String errorMessage = "";
                Byte[] input_buffer = new Byte[512];
                Int32 c;
                Boolean l_endQuery = false;
                while (!l_endQuery)
                {
                    c = (Char)stream.ReadByte();

                    switch (c)
                    {
                    case 'A':	// Asynchronous Notify
                        //TODO: do something with this
                        Int32 pid = PGUtil.ReadInt32(stream,input_buffer);
                        String msg = PGUtil.ReadString(stream,conn.Connector.Encoding);


                        conn.Connector.CheckErrorsAndNotifications();

                        break;

                        //------------------------------
                        // Error message returned
                    case 'E':
                        NpgsqlError e = new NpgsqlError(conn.BackendProtocolVersion);
                        e.ReadFromStream(stream,conn.Connector.Encoding);
                        errorMessage +=  e.Message;
                        break;

                        //------------------------------
                        // Notice from backend
                    case 'N':
                        NpgsqlError notice = new NpgsqlError(conn.BackendProtocolVersion);
                        notice.ReadFromStream(stream,conn.Connector.Encoding);
                        errorMessage +=  notice.Message;
                        break;

                    case 'V':
                        Char l_nextChar = (Char)stream.ReadByte();
                        if (l_nextChar == 'G')
                        {
                            Int32 sz = PGUtil.ReadInt32(stream,input_buffer);
                            // Return an Integer if
                            if (resulttype)
                                result = PGUtil.ReadInt32(stream,input_buffer);
                            else
                            {
                                Byte[] buf = new Byte[sz];

                                Int32 bytes_from_stream = 0;
                                Int32 total_bytes_read = 0;
                                Int32 size = sz;
                                do
                                {
                                    bytes_from_stream = stream.Read(buf, total_bytes_read, size);
                                    total_bytes_read += bytes_from_stream;
                                    size -= bytes_from_stream;
                                }
                                while(size > 0);

                                result = buf;
                            }
                            //There should be a trailing '0'
                            Int32 l_endChar = (Char)stream.ReadByte();
                        }
                        else
                        {
                            //it must have been a '0', thus no results
                        }
                        break;

                    case 'Z':
                        l_endQuery = true;
                        break;

                    default:
                        throw new Exception("postgresql.fp.protocol " + c.ToString());
                    }
                }

                if ( errorMessage != null )
                    throw new Exception("postgresql.fp.error" + errorMessage);

                return result;
            }
        }
Пример #6
0
        private Object FastpathV3(Int32 fnid, Boolean resulttype, FastpathArg[] args)
        {
            // give  thread safety
            lock (stream)
            {
                // send the function call
                try
                {
                    Int32 l_msgLen = 0;
                    l_msgLen += 16;
                    for (Int32 i=0;i < args.Length;i++)
                        l_msgLen += args[i].SendSize();

                    stream.WriteByte((Byte)'F');
                    PGUtil.WriteInt32(stream,l_msgLen);
                    PGUtil.WriteInt32(stream,fnid);
                    PGUtil.WriteInt16(stream,1);
                    PGUtil.WriteInt16(stream,1);
                    PGUtil.WriteInt16(stream,(short)args.Length);

                    for (Int32 i = 0;i < args.Length;i++)
                        args[i].Send(stream);

                    PGUtil.WriteInt16(stream,1);

                    // This is needed, otherwise data can be lost
                    stream.Flush();

                }
                catch (Exception ex)
                {
                    throw new Exception(ex.ToString());
                }

                // Now handle the result

                // Now loop, reading the results
                Object result = null; // our result
                Exception error = null;
                Int32 c;
                Boolean l_endQuery = false;
                Byte[] input_buffer = new Byte[512];

                while (!l_endQuery)
                {
                    c = (Char)stream.ReadByte();

                    switch (c)
                    {
                    case 'A':	// Asynchronous Notify
                        Int32 msglen = PGUtil.ReadInt32(stream,input_buffer);
                        Int32 pid = PGUtil.ReadInt32(stream,input_buffer);
                        String msg = PGUtil.ReadString(stream,conn.Connector.Encoding);
                        PGUtil.ReadString(stream,conn.Connector.Encoding);
                        String param = PGUtil.ReadString(stream,conn.Connector.Encoding);

                        conn.Connector.CheckErrorsAndNotifications();
                        break;
                        //------------------------------
                        // Error message returned
                    case 'E':
                        NpgsqlError e = new NpgsqlError(conn.BackendProtocolVersion);
                        e.ReadFromStream(stream,conn.Connector.Encoding);
                        throw new Exception(e.ToString());

                        //------------------------------
                        // Notice from backend
                    case 'N':
                        Int32 l_nlen = PGUtil.ReadInt32(stream,input_buffer);

                        NpgsqlError e1 = new NpgsqlError(conn.BackendProtocolVersion);
                        e1.ReadFromStream(stream,conn.Connector.Encoding);
                        conn.Connector.Mediator.Errors.Add(e1);

                        break;

                    case 'V':
                        Int32 l_msgLen = PGUtil.ReadInt32(stream,input_buffer);
                        Int32 l_valueLen = PGUtil.ReadInt32(stream,input_buffer);

                        if (l_valueLen == -1)
                        {
                            //null value
                        }
                        else if (l_valueLen == 0)
                        {
                            result = new Byte[0];
                        }
                        else
                        {
                            // Return an Integer if
                            if (resulttype)

                                result = PGUtil.ReadInt32(stream,input_buffer);
                            else
                            {
                                Byte[] buf = new Byte[l_valueLen];

                                Int32 bytes_from_stream = 0;
                                Int32 total_bytes_read = 0;
                                Int32 size = l_valueLen;
                                do
                                {
                                    bytes_from_stream = stream.Read(buf, total_bytes_read, size);
                                    total_bytes_read += bytes_from_stream;
                                    size -= bytes_from_stream;
                                }
                                while(size > 0);

                                result = buf;
                            }
                        }
                        break;

                    case 'Z':
                        //TODO: use size better
                        if (PGUtil.ReadInt32(stream,input_buffer) != 5)
                            throw new Exception("Received Z" );
                        //TODO: handle transaction status
                        Char l_tStatus = (Char)stream.ReadByte();
                        l_endQuery = true;
                        break;

                    default:
                        throw new Exception("postgresql.fp.protocol received " + c.ToString());
                    }
                }

                if ( error != null )
                    throw error;

                return result;
            }
        }