Hackers Magazine 57/CdHackersMagazineNr57.iso/Software/Networking/nmap-5.00-setup.exe/nselib/msrpcperformance.lua

Text File | 2009-07-06 | 29KB | 612 lines

---This module is designed to parse the <code>PERF_DATA_BLOCK</code> structure, which is
-- stored in the registry under HKEY_PERFORMANCE_DATA. By querying this structure, you can
-- get a whole lot of information about what's going on.
--
-- To use this from a script, see <code>get_performance_data</code>, it is the only
-- 'public' function in this module.
--
-- My primary sources of information were:
-- * This 1996 journal by Matt Pietrek: <http://www.microsoft.com/msj/archive/S271.aspx>
-- * The followup article: <http://www.microsoft.com/msj/archive/S2A9.aspx>
-- * The WinPerf.h header file
--
-- And my primary inspiration was PsTools, specifically, pstasklist.exe.
--
--@author Ron Bowes <[e-mail]>
--@copyright Same as Nmap--See http://nmap.org/book/man-legal.html
-----------------------------------------------------------------------
module(... or "msrpcperformance", package.seeall)

require 'msrpctypes'

---Parses the title database, which is a series of null-terminated string pairs.
--
--@param data     The data being processed.
--@param pos      The position within <code>data</code>.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_title_database(data, pos)
    local result = {}
    local i = 1

    repeat
        local number, name
        pos, number, name = bin.unpack("<zz", data, pos)

        if(number == nil) then
            return false, "Couldn't parse the title database: end of string encountered early"
        elseif(tonumber(number) == nil) then -- Not sure if this actually happens, but it doesn't hurt to check
            stdnse.print_debug(1, "MSRPC: ERROR: Couldn't parse the title database: string found where number expected (%d: '%s')", i, number)
            return false, "Couldn't parse the title database"
        end

        result[tonumber(number)] = name
        i = i + 1
    until pos >= #data

    return true, pos, result
end

---Parses a PERF_DATA_BLOCK, which has the following definition (from "WinPerf.h" on Visual Studio 8):
--
--<code>
--    typedef struct _PERF_DATA_BLOCK {
--        WCHAR           Signature[4];       // Signature: Unicode "PERF"
--        DWORD           LittleEndian;       // 0 = Big Endian, 1 = Little Endian
--        DWORD           Version;            // Version of these data structures
--                                            // starting at 1
--        DWORD           Revision;           // Revision of these data structures
--                                            // starting at 0 for each Version
--        DWORD           TotalByteLength;    // Total length of data block
--        DWORD           HeaderLength;       // Length of this structure
--        DWORD           NumObjectTypes;     // Number of types of objects
--                                            // being reported
--        LONG            DefaultObject;      // Object Title Index of default
--                                            // object to display when data from
--                                            // this system is retrieved (-1 =
--                                            // none, but this is not expected to
--                                            // be used)
--        SYSTEMTIME      SystemTime;         // Time at the system under
--                                            // measurement
--        LARGE_INTEGER   PerfTime;           // Performance counter value
--                                            // at the system under measurement
--        LARGE_INTEGER   PerfFreq;           // Performance counter frequency
--                                            // at the system under measurement
--        LARGE_INTEGER   PerfTime100nSec;    // Performance counter time in 100 nsec
--                                            // units at the system under measurement
--        DWORD           SystemNameLength;   // Length of the system name
--        DWORD           SystemNameOffset;   // Offset, from beginning of this
--                                            // structure, to name of system
--                                            // being measured
--    } PERF_DATA_BLOCK, *PPERF_DATA_BLOCK;
--</code>
--
--@param data     The data being processed.
--@param pos      The position within <code>data</code>.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_data_block(data, pos)
    local result = {}

    pos, result['Signature'] = msrpctypes.unicode_to_string(data, pos, 4, false)
    if(result['Signature'] ~= "PERF") then
        return false, "MSRPC: PERF_DATA_BLOCK signature is missing or incorrect"
    end

    pos, result['LittleEndian'] = msrpctypes.unmarshall_int32(data, pos)
    if(result['LittleEndian'] ~= 1) then
        return false, "MSRPC: PERF_DATA_BLOCK returned a non-understood endianness"
    end

    -- Parse the header
    pos, result['Version']          = msrpctypes.unmarshall_int32(data, pos)
    pos, result['Revision']         = msrpctypes.unmarshall_int32(data, pos)
    pos, result['TotalByteLength']  = msrpctypes.unmarshall_int32(data, pos)
    pos, result['HeaderLength']     = msrpctypes.unmarshall_int32(data, pos)
    pos, result['NumObjectTypes']   = msrpctypes.unmarshall_int32(data, pos)
    pos, result['DefaultObject']    = msrpctypes.unmarshall_int32(data, pos)
    pos, result['SystemTime']       = msrpctypes.unmarshall_SYSTEMTIME(data, pos)
    pos, result['PerfTime']         = msrpctypes.unmarshall_int64(data, pos)
    pos, result['PerfFreq']         = msrpctypes.unmarshall_int64(data, pos)
    pos, result['PerfTime100nSec']  = msrpctypes.unmarshall_int64(data, pos)
    pos = pos + 4 -- This value doesn't seem to line up, so add 4

    pos, result['SystemNameLength'] = msrpctypes.unmarshall_int32(data, pos)
    pos, result['SystemNameOffset'] = msrpctypes.unmarshall_int32(data, pos)

    -- Ensure that the system name is directly after the header. This technically shouldn't matter, but Microsoft's documentation
    -- (in WinPref.h) says that the actual object comes "after the PERF_DATA_BLOCK", so it doesn't make sense that the SystemName
    -- could be anywhere else.
    if(pos ~= result['SystemNameOffset'] + 1) then
        return false, "MSRPC: PERF_DATA_BLOCK has SystemName in the wrong location"
    end

    -- Read the system name from the next location (which happens to be identical to SystemNameOffset, on a proper system)
    pos, result['SystemName'] = msrpctypes.unicode_to_string(data, pos, result['SystemNameLength'] / 2, true)

    pos = pos + 4 -- Again, we end up not lined up so here we fix it

    return true, pos, result
end


---Parse a PERF_OBJECT_TYPE structure. From Microsoft's documentation:
--
--<code>
-- //
-- //  The _PERF_DATA_BLOCK structure is followed by NumObjectTypes of
-- //  data sections, one for each type of object measured.  Each object
-- //  type section begins with a _PERF_OBJECT_TYPE structure.
-- //
-- typedef struct _PERF_OBJECT_TYPE {
--         DWORD           TotalByteLength;    // Length of this object definition
--                                             // including this structure, the
--                                             // counter definitions, and the
--                                             // instance definitions and the
--                                             // counter blocks for each instance:
--                                             // This is the offset from this
--                                             // structure to the next object, if
--                                             // any
--         DWORD           DefinitionLength;   // Length of object definition,
--                                             // which includes this structure
--                                             // and the counter definition
--                                             // structures for this object: this
--                                             // is the offset of the first
--                                             // instance or of the counters
--                                             // for this object if there is
--                                             // no instance
--         DWORD           HeaderLength;       // Length of this structure: this
--                                             // is the offset to the first
--                                             // counter definition for this
--                                             // object
--         DWORD           ObjectNameTitleIndex;
--                                             // Index to name in Title Database
-- #ifdef _WIN64
--         DWORD           ObjectNameTitle;    // Should use this as an offset
-- #else
--         LPWSTR          ObjectNameTitle;    // Initially NULL, for use by
--                                             // analysis program to point to
--                                             // retrieved title string
-- #endif
--         DWORD           ObjectHelpTitleIndex;
--                                             // Index to Help in Title Database
-- #ifdef _WIN64
--         DWORD           ObjectHelpTitle;    // Should use this as an offset
-- #else
--         LPWSTR          ObjectHelpTitle;    // Initially NULL, for use by
--                                             // analysis program to point to
--                                             // retrieved title string
-- #endif
--         DWORD           DetailLevel;        // Object level of detail (for
--                                             // controlling display complexity);
--                                             // will be min of detail levels
--                                             // for all this object's counters
--         DWORD           NumCounters;        // Number of counters in each
--                                             // counter block (one counter
--                                             // block per instance)
--         LONG            DefaultCounter;     // Default counter to display when
--                                             // this object is selected, index
--                                             // starting at 0 (-1 = none, but
--                                             // this is not expected to be used)
--         LONG            NumInstances;       // Number of object instances
--                                             // for which counters are being
--                                             // returned from the system under
--                                             // measurement. If the object defined
--                                             // will never have any instance data
--                                             // structures (PERF_INSTANCE_DEFINITION)
--                                             // then this value should be -1, if the
--                                             // object can have 0 or more instances,
--                                             // but has none present, then this
--                                             // should be 0, otherwise this field
--                                             // contains the number of instances of
--                                             // this counter.
--         DWORD           CodePage;           // 0 if instance strings are in
--                                             // UNICODE, else the Code Page of
--                                             // the instance names
--         LARGE_INTEGER   PerfTime;           // Sample Time in "Object" units
--                                             //
--         LARGE_INTEGER   PerfFreq;           // Frequency of "Object" units in
--                                             // counts per second.
-- } PERF_OBJECT_TYPE, *PPERF_OBJECT_TYPE;
--</code>
--
--@param data           The data being processed.
--@param pos            The position within <code>data</code>.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_object_type(data, pos)
    local result = {}

    pos, result['TotalByteLength']      = msrpctypes.unmarshall_int32(data, pos) -- Offset to the next object
    pos, result['DefinitionLength']     = msrpctypes.unmarshall_int32(data, pos) -- Offset to the first instance (or counter, if no instances)
    pos, result['HeaderLength']         = msrpctypes.unmarshall_int32(data, pos) -- Offset to the first counter definition
    pos, result['ObjectNameTitleIndex'] = msrpctypes.unmarshall_int32(data, pos) -- Index in the Title Database
    pos, result['ObjectNameTitle']      = msrpctypes.unmarshall_int32(data, pos) -- TODO: will this work with 64-bit?
    pos, result['ObjectHelpTitleIndex'] = msrpctypes.unmarshall_int32(data, pos) -- Index in the Help Database
    pos, result['ObjectHelpTitle']      = msrpctypes.unmarshall_int32(data, pos) -- TODO: will this workw ith 64-bit?
    pos, result['DetailLevel']          = msrpctypes.unmarshall_int32(data, pos)
    pos, result['NumCounters']          = msrpctypes.unmarshall_int32(data, pos) -- The number of counters in each counter block
    pos, result['DefaultCounter']       = msrpctypes.unmarshall_int32(data, pos)
    pos, result['NumInstances']         = msrpctypes.unmarshall_int32(data, pos) -- Numer of object instances for which counters are being returned
    pos, result['CodePage']             = msrpctypes.unmarshall_int32(data, pos) -- 0 if strings are in UNICODE, otherwise the Code Page
--    if(result['CodePage'] ~= 0) then
--        return false, string.format("Unknown Code Page for data: %d\n", result['CodePage'])
--    end
    pos, result['PerfTime']             = msrpctypes.unmarshall_int64(data, pos) -- Sample time in "Object" units
    pos, result['PerfFreq']             = msrpctypes.unmarshall_int64(data, pos) -- Frequency of "Object" units in counts/second

    return true, pos, result
end


---Parse a PERF_COUNTER_DEFINITION structure. From Microsoft's documentation:
--
--<code>
--    //  There is one of the following for each of the
--    //  PERF_OBJECT_TYPE.NumCounters.  The Unicode names in this structure MUST
--    //  come from a message file.
--    typedef struct _PERF_COUNTER_DEFINITION {
--        DWORD           ByteLength;         // Length in bytes of this structure
--        DWORD           CounterNameTitleIndex;
--                                            // Index of Counter name into
--                                            // Title Database
--    #ifdef _WIN64
--        DWORD           CounterNameTitle;
--    #else
--        LPWSTR          CounterNameTitle;   // Initially NULL, for use by
--                                            // analysis program to point to
--                                            // retrieved title string
--    #endif
--        DWORD           CounterHelpTitleIndex;
--                                            // Index of Counter Help into
--                                            // Title Database
--    #ifdef _WIN64
--        DWORD           CounterHelpTitle;
--    #else
--        LPWSTR          CounterHelpTitle;   // Initially NULL, for use by
--                                            // analysis program to point to
--                                            // retrieved title string
--    #endif
--        LONG            DefaultScale;       // Power of 10 by which to scale
--                                            // chart line if vertical axis is 100
--                                            // 0 ==> 1, 1 ==> 10, -1 ==>1/10, etc.
--        DWORD           DetailLevel;        // Counter level of detail (for
--                                            // controlling display complexity)
--        DWORD           CounterType;        // Type of counter
--        DWORD           CounterSize;        // Size of counter in bytes
--        DWORD           CounterOffset;      // Offset from the start of the
--                                            // PERF_COUNTER_BLOCK to the first
--                                            // byte of this counter
--    } PERF_COUNTER_DEFINITION, *PPERF_COUNTER_DEFINITION;
--</code>
--
--@param data           The data being processed.
--@param pos            The position within <code>data</code>.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_counter_definition(data, pos)
    local result = {}
    local initial_pos = pos

    pos, result['ByteLength']            = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterNameTitleIndex'] = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterNameTitle']      = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterHelpTitleIndex'] = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterHelpTitle']      = msrpctypes.unmarshall_int32(data, pos)
    pos, result['DefaultScale']          = msrpctypes.unmarshall_int32(data, pos)
    pos, result['DetailLevel']           = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterType']           = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterSize']           = msrpctypes.unmarshall_int32(data, pos)
    pos, result['CounterOffset']         = msrpctypes.unmarshall_int32(data, pos)

    pos = initial_pos + result['ByteLength']

    return true, pos, result
end

---Parse the actual counter value. This is a fairly simple function, it takes a counter
-- definition and pulls out data based on it.
--
-- Note: I don't think this is doing the 8-byte values right, I suspect that they're supposed
-- to be doubles.
--
--@param data           The data being processed.
--@param pos            The position within <code>data</code>.
--@param counter_definition The matching counter_definition.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_counter(data, pos, counter_definition)
    local result

    if(counter_definition['CounterSize'] == 4) then
        pos, result = msrpctypes.unmarshall_int32(data, pos)
    elseif(counter_definition['CounterSize'] == 8) then
        pos, result = msrpctypes.unmarshall_int64(data, pos)
--        pos, result = bin.unpack("<d", data, pos)
    else
        pos, result = msrpctypes.unmarshall_raw(data, pos, counter_definition['CounterSize'])
    end

    return true, pos, result
end

---Parse a PERF_INSTANCE_DEFINITION structure. From Microsoft's documentation:
--
--<code>
--    //  If (PERF_DATA_BLOCK.NumInstances >= 0) then there will be
--    //  PERF_DATA_BLOCK.NumInstances of a (PERF_INSTANCE_DEFINITION
--    //  followed by a PERF_COUNTER_BLOCK followed by the counter data fields)
--    //  for each instance.
--    //
--    //  If (PERF_DATA_BLOCK.NumInstances < 0) then the counter definition
--    //  strucutre above will be followed by only a PERF_COUNTER_BLOCK and the
--    //  counter data for that COUNTER.
--    typedef struct _PERF_INSTANCE_DEFINITION {
--        DWORD           ByteLength;         // Length in bytes of this structure,
--                                            // including the subsequent name
--        DWORD           ParentObjectTitleIndex;
--                                            // Title Index to name of "parent"
--                                            // object (e.g., if thread, then
--                                            // process is parent object type);
--                                            // if logical drive, the physical
--                                            // drive is parent object type
--        DWORD           ParentObjectInstance;
--                                            // Index to instance of parent object
--                                            // type which is the parent of this
--                                            // instance.
--        LONG            UniqueID;           // A unique ID used instead of
--                                            // matching the name to identify
--                                            // this instance, -1 = none
--        DWORD           NameOffset;         // Offset from beginning of
--                                            // this struct to the Unicode name
--                                            // of this instance
--        DWORD           NameLength;         // Length in bytes of name; 0 = none
--                                            // this length includes the characters
--                                            // in the string plus the size of the
--                                            // terminating NULL char. It does not
--                                            // include any additional pad bytes to
--                                            // correct structure alignment
--    } PERF_INSTANCE_DEFINITION, *PPERF_INSTANCE_DEFINITION;
--</code>
--
--@param data           The data being processed.
--@param pos            The position within <code>data</code>.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_instance_definition(data, pos)
    local result = {}

    -- Remember where we started. I noticed that where the counter part starts can move around, so we have to
    -- determine it by adding ByteLength to the initial position
    local initial_pos = pos

    pos, result['ByteLength']             = msrpctypes.unmarshall_int32(data, pos)
    pos, result['ParentObjectTitleIndex'] = msrpctypes.unmarshall_int32(data, pos)
    pos, result['ParentObjectInstance']   = msrpctypes.unmarshall_int32(data, pos)
    pos, result['UniqueID']               = msrpctypes.unmarshall_int32(data, pos)
    pos, result['NameOffset']             = msrpctypes.unmarshall_int32(data, pos)
    pos, result['NameLength']             = msrpctypes.unmarshall_int32(data, pos)

    pos, result['InstanceName']           = msrpctypes.unicode_to_string(data, pos, result['NameLength'] / 2, true)

    pos = initial_pos + result['ByteLength']

    return true, pos, result
end

---Parse a PERF_COUNTER_BLOCK structure. From Microsoft's documentation:
--
--<code>
--    typedef struct _PERF_COUNTER_BLOCK {
--        DWORD           ByteLength;         // Length in bytes of this structure,
--                                            // including the following counters
--    } PERF_COUNTER_BLOCK, *PPERF_COUNTER_BLOCK;
--
--</code>
--
--@param data           The data being processed.
--@param pos            The position within <code>data</code>.
--@return (status, pos, result) The status (true if successful), the new position in <code>data</code> (or an error
--                              message), and a table representing the datatype, if any.
local function parse_perf_counter_block(data, pos)
    local result = {}

    pos, result['ByteLength'] = msrpctypes.unmarshall_int32(data, pos)

    return true, pos, result
end

---Retrieve the parsed performance data from the given host for the requested object values. To get a list of possible
-- object values, leave 'objects' blank and look at <code>result['title_database']</code> -- it'll contain a list of
-- indexes that can be looked up. These indexes are passed as a string or as a series of space-separated strings (eg,
-- "230" for "Process" and "238" for "Process" and "Processor").
--
--@param host The host object
--@param objects [optional] The space-separated list of object numbers to retrieve. Default: only retrieve the database.
function get_performance_data(host, objects)

    local status, smbstate
    local bind_result, openhkpd_result, queryvalue_result, data_block
    local pos
    local result = {}
    local i, j, k
    local pos

    -- Create the SMB session
    status, smbstate = msrpc.start_smb(host, msrpc.WINREG_PATH)
    if(status == false) then
        return false, smbstate
    end

    -- Bind to WINREG service
    status, bind_result = msrpc.bind(smbstate, msrpc.WINREG_UUID, msrpc.WINREG_VERSION, nil)
    if(status == false) then
        msrpc.stop_smb(smbstate)
        return false, bind_result
    end

    -- Open HKEY_PERFORMANCE_DATA
    status, openhkpd_result = msrpc.winreg_openhkpd(smbstate)
    if(status == false) then
        msrpc.stop_smb(smbstate)
        return false, openhkpd_result
    end

    status, queryvalue_result = msrpc.winreg_queryvalue(smbstate, openhkpd_result['handle'], "Counter 009")
    if(status == false) then
        msrpc.stop_smb(smbstate)
        return false, queryvalue_result
    end

    -- Parse the title database
    pos = 1
    status, pos, result['title_database'] = parse_perf_title_database(queryvalue_result['value'], pos)
    if(status == false) then
        msrpc.stop_smb(smbstate)
        return false, pos
    end
    result['title_database'][0] = "<null>"


    if(objects ~= nil and #objects > 0) then
        -- Query for the objects
        status, queryvalue_result = msrpc.winreg_queryvalue(smbstate, openhkpd_result['handle'], objects)
        if(status == false) then
            msrpc.stop_smb(smbstate)
            return false, queryvalue_result
        end

        -- Parse the header
        pos = 1
        status, pos, data_block = parse_perf_data_block(queryvalue_result['value'], pos)
        if(status == false) then
            msrpc.stop_smb(smbstate)
            return false, pos
        end

        -- Move past the header
        pos = 1 + data_block['HeaderLength']

        -- Parse the data sections
        for i = 1, data_block['NumObjectTypes'], 1 do
            local object_start = pos
            local object_name

            local counter_definitions = {}
            local object_instances    = {}
            local counter_definitions = {}

            -- Get the type of the object (this is basically the class definition -- info about the object instances)
            status, pos, object_type = parse_perf_object_type(queryvalue_result['value'], pos)
            if(status == false) then
                msrpc.stop_smb(smbstate)
                return false, pos
            end

            -- Start setting up the result object
--io.write(string.format("Index = %d\n", object_type['ObjectNameTitleIndex']))
            object_name = result['title_database'][object_type['ObjectNameTitleIndex']]
            result[object_name] = {}

--io.write(string.format("\n\nOBJECT: %s\n", object_name))
--io.write(string.format(" Counters: %d\n", object_type['NumCounters']))
--io.write(string.format(" Instances: %d\n", object_type['NumInstances']))
--io.write("-----------------\n")

            -- Bring the position to the beginning of the counter definitions
            pos = object_start + object_type['HeaderLength']

            -- Parse the counter definitions
            for j = 1, object_type['NumCounters'], 1 do
                status, pos, counter_definitions[j] = parse_perf_counter_definition(queryvalue_result['value'], pos)
                if(status == false) then
                    msrpc.stop_smb(smbstate)
                    return false, pos
                end
--io.write(string.format(" Counter definition #%2d: [%d bytes] %s\n", j, counter_definitions[j]['CounterSize'], result['title_database'][counter_definitions[j]['CounterNameTitleIndex']]))
            end

            -- Bring the position to the beginning of the instances (or counters)
            pos = object_start + object_type['DefinitionLength']

            -- Check if we have any instances (sometimes we don't -- if we don't, the value returned is a negative)
            if(bit.band(object_type['NumInstances'], 0x80000000) == 0) then
                -- Parse the object instances and counters
                for j = 1, object_type['NumInstances'], 1 do
                    local instance_start = pos
                    local instance_name
                    local counter_block
                    -- Instance definition
                    status, pos, object_instances[j] = parse_perf_instance_definition(queryvalue_result['value'], pos)
                    if(status == false) then
                        msrpc.stop_smb(smbstate)
                        return false, pos
                    end

                    -- Set up the instance array
                    instance_name = object_instances[j]['InstanceName']
                    result[object_name][instance_name] = {}

                    -- Bring the pos to the start of the counter block
                    pos = instance_start + object_instances[j]['ByteLength']

--io.write(string.format("\n  INSTANCE: %s\n", instance_name))
--io.write(string.format("  Length: %d\n",     object_instances[j]['ByteLength']))
--io.write(string.format("  NameOffset: %d\n", object_instances[j]['NameOffset']))
--io.write(string.format("  NameLength: %d\n", object_instances[j]['NameLength']))
--io.write("  --------------\n")

                    -- The counter block
                    status, pos, counter_block = parse_perf_counter_block(queryvalue_result['value'], pos)
                    if(status == false) then
                        msrpc.stop_smb(smbstate)
                        return false, pos
                    end

                    for k = 1, object_type['NumCounters'], 1 do
                        local counter_name
                        -- Each individual counter
                        status, pos, counter_result = parse_perf_counter(queryvalue_result['value'], pos, counter_definitions[k])
                        if(status == false) then
                            msrpc.stop_smb(smbstate)
                            return false, pos
                        end
                        counter_name = result['title_database'][counter_definitions[k]['CounterNameTitleIndex']]
--io.write(string.format("    %s: %s\n", counter_name, counter_result))

                        -- Save it in the result
                        result[object_name][instance_name][counter_name] = counter_result
                    end

                    -- Bring the pos to the end of the next section
                    pos = instance_start + object_instances[j]['ByteLength'] + counter_block['ByteLength']
                end
            else
                for k = 1, object_type['NumCounters'], 1 do
                    local counter_name
                    -- Each individual counter
                    status, pos, counter_result = parse_perf_counter(queryvalue_result['value'], pos, counter_definitions[k])
                    if(status == false) then
                        msrpc.stop_smb(smbstate)
                        return false, pos
                    end
                    counter_name = result['title_database'][counter_definitions[k]['CounterNameTitleIndex']]
--io.write(string.format("    %s: %s\n", counter_name, counter_result))

                    -- Save it in the result
                    result[object_name][counter_name] = counter_result
                end
            end
        end

        -- Blank out the database
        result['title_database'] = nil
    end

    msrpc.stop_smb(smbstate)

    return true, result
end