SRV records for a specific domain

[AdmiralAlkex]

I needed a way to get SRV records for domains, and the closest I found was >this thread, but no, it was not as easy to 'upgrade' as trancexx said!

A summary of my changes:

• Replaced MX specifics with SRV specifics (obviously...)
• Adapted the code to work with _ArraySort() instead of her custom SortArray (seemed easier than adding the extra logic I needed)
• Replaced the non-working RegRead with a DllCall to GetNetworkParams (not sure if that key moved or if it never was there to begin with)
• Added Googles dns servers to list of public ones and simplified list code
• Fixed a bug in ExtractSRVServerData() that garbled data if more than 1 record was received

Enjoy!

expandcollapse popup

#Region ;**** Directives created by AutoIt3Wrapper_GUI ****
#AutoIt3Wrapper_UseX64=n
#EndRegion ;**** Directives created by AutoIt3Wrapper_GUI ****

#cs
    Originally was a script to get MX records written by trancexx
    http://www.autoitscript.com/forum/topic/78465-mx-records-for-a-specific-domain/

    Now modified to get SRV records by AdmiralAlkex
#ce

Opt("MustDeclareVars", 1)


#include <StringConstants.au3>
#include <Array.au3>


Local $domain = "_sip._udp.siplogin.de" ; change it to domain of your interest

Local $mx = SRVRecords($domain)

If IsArray($mx) Then
    Local $au
    For $j = 0 To UBound($mx) - 1
        $au &= "Priority:" & $mx[$j][0] & " Weight:" & $mx[$j][1] & " Port:" & $mx[$j][2] & " Target:" & $mx[$j][3] & @CRLF
    Next

    MsgBox(0, "SRV records for " & $domain, $au)
Else
    MsgBox(0, "SRV records for " & $domain, "No Records")
EndIf



Func SRVRecords($domain)

    Local $binary_data = SRVQueryServer($domain)
    If $binary_data = -1 Then Return -1

    Local $output = ExtractSRVServerData($binary_data)

    _ArraySort($output, 0, 0, 0, 0)

    Local $iStart = -1
    For $iX = 1 To UBound($output) - 1
        If $output[$iX][0] = $output[$iX - 1][0] And $iStart = -1 Then
            $iStart = $iX - 1
        ElseIf $output[$iX][0] <> $output[$iX - 1][0] And $iStart <> -1 Then
            _ArraySort($output, 1, $iStart, $iX - 1, 1)
            $iStart = -1
        EndIf
    Next
    If $iStart <> -1 Then
        _ArraySort($output, 1, $iStart, $iX - 1, 1)
    EndIf

    Return $output

EndFunc   ;==>SRVRecords


Func SRVQueryServer($domain)

    Local $domain_array
    $domain_array = StringSplit($domain, ".", 1)

    Local $binarydom
    For $el = 1 To $domain_array[0]
        $binarydom &= Hex(BinaryLen($domain_array[$el]), 2) & StringTrimLeft(StringToBinary($domain_array[$el]), 2)
    Next
    $binarydom &= "00" ; for example, 'gmail.com' will be '05676D61696C03636F6D00' and 'autoit.com' will be '066175746F697403636F6D00'

    Local $identifier = Hex(Random(0, 1000, 1), 2) ; random hex number serving as a handle for the data that will be received
    Local $server_bin = "0x00" & $identifier & "01000001000000000000" & $binarydom & "00210001" ; this is our query
    Local $num_time, $data

    Local $asQueryServers = _GetDnsServerAddress()
    Local $asPublicServers = StringSplit("8.8.8.8|8.8.4.4|4.2.2.1|67.138.54.100|208.67.222.222|4.2.2.2|4.2.2.3|208.67.220.220|4.2.2.4|4.2.2.5|4.2.2.6", "|", $STR_NOCOUNT)
    Local $iSize = _ArrayConcatenate($asQueryServers, $asPublicServers)

    For $num_time = 0 To $iSize - 1
        ; this kind of server is not what we want
        If StringLeft($asQueryServers[$num_time], 3) = "192" Then ContinueLoop
        If $asQueryServers[$num_time] = "" Then ContinueLoop

        UDPStartup()

        Local $sock
        $sock = UDPOpen($asQueryServers[$num_time], 53)
        If $sock = -1 Then ; ok, that happens
            UDPCloseSocket($sock)
            UDPShutdown()
            ContinueLoop ; change server and try again
        EndIf

        UDPSend($sock, $server_bin) ; sending query

        Local $tik = 0
        Do
            $data = UDPRecv($sock, 512)
            $tik += 1
            Sleep(100)
        Until $data <> "" Or $tik = 8 ; waiting reasonable time for the response

        UDPShutdown() ; stopping service

        If $data <> "" And StringRight(BinaryMid($data, 2, 1), 2) = $identifier Then
            Return $data ; if there is data for us, return
        EndIf
    Next

    Return -1

EndFunc   ;==>SRVQueryServer


Func ExtractSRVServerData($binary_data)

    Local $num_answ = Dec(StringMid($binary_data, 15, 4)) ; representing number of answers provided by the server

    Local $arr = StringSplit($binary_data, "C00C00210001", 1) ; splitting input; "C00C000F0001" - translated to human: "this is the answer for your MX query"

    If $num_answ <> $arr[0] - 1 Or $num_answ = 0 Then Return -1 ; dealing with possible options

    Local $iPriority[$arr[0]]
    Local $iWeight[$arr[0]]
    Local $iPort[$arr[0]]
    Local $sTarget[$arr[0]] ; server name(s)
    Local $output[$arr[0] - 1][4] ; this goes out containing both server names and coresponding priority/weight and port numbers

    Local $offset = 14 ; initial offset

    For $i = 2 To $arr[0]

        $arr[$i] = "0x" & $arr[$i] ; well, it is binary data

        $iPriority[$i - 1] = Dec(StringRight(BinaryMid($arr[$i], 7, 2), 4))

        $iWeight[$i - 1] = Dec(StringRight(BinaryMid($arr[$i], 9, 2), 4))

        $iPort[$i - 1] = Dec(StringRight(BinaryMid($arr[$i], 11, 2), 4))

        $offset += BinaryLen($arr[$i - 1]) + 6 ; adding lenght of every past part plus lenght of that "C00C000F0001" used for splitting

        Local $array = ReadBinary($binary_data, $offset) ; extraction of server names starts here

        While $array[1] = 192 ; dealing with special case
            $array = ReadBinary($binary_data, $array[6] + 2)
        WEnd

        $sTarget[$i - 1] &= $array[2] & "."

        While $array[3] <> 0 ; the end will obviously be at $array[3] = 0

            If $array[3] = 192 Then

                $array = ReadBinary($array[0], $array[4] + 2)

                If $array[3] = 0 Then
                    $sTarget[$i - 1] &= $array[2]
                    ExitLoop
                Else
                    $sTarget[$i - 1] &= $array[2] & "."
                EndIf

            Else

                $array = ReadBinary($array[0], $array[5])

                If $array[3] = 0 Then
                    $sTarget[$i - 1] &= $array[2]
                    ExitLoop
                Else
                    $sTarget[$i - 1] &= $array[2] & "."
                EndIf

            EndIf

        WEnd

        $output[$i - 2][0] = $iPriority[$i - 1]
        $output[$i - 2][1] = $iWeight[$i - 1]
        $output[$i - 2][2] = $iPort[$i - 1]
        $output[$i - 2][3] = $sTarget[$i - 1]

    Next

    Return $output ; two-dimensional array

EndFunc   ;==>ExtractSRVServerData


Func ReadBinary($binary_data, $offset)

    Local $len = Dec(StringRight(BinaryMid($binary_data, $offset - 1, 1), 2))

    Local $data_bin = BinaryMid($binary_data, $offset, $len)

    Local $checker = Dec(StringRight(BinaryMid($data_bin, 1, 1), 2))

    Local $data = BinaryToString($data_bin)

    Local $triger = Dec(StringRight(BinaryMid($binary_data, $offset + $len, 1), 2))

    Local $new_offset = Dec(StringRight(BinaryMid($binary_data, $offset + $len + 1, 1), 2))

    Local $another_offset = $offset + $len + 1

    Local $array[7] = [$binary_data, $len, $data, $triger, $new_offset, $another_offset, $checker] ; bit of this and bit of that

    Return $array

EndFunc   ;==>ReadBinary

;Based on Authenticity code from http://www.autoitscript.com/forum/topic/119734-tcpiptoname-extremly-slow-if-no-ptr-record-exists/?p=832148
Func _GetDnsServerAddress()
    Local $aResult, $tBuf, $tDnsServersList

    $aResult = DllCall("iphlpapi.dll", "uint", "GetNetworkParams", "int*", 0, "uint*", 4)

    If $aResult[0] = 111 Then
        $tBuf = DllStructCreate("byte[" & $aResult[2] & "]")
        $aResult = DllCall("iphlpapi.dll", "uint", "GetNetworkParams", "struct*", $tBuf, "uint*", $aResult[2])
        If $aResult[0] <> 0 Then Return SetError($aResult[0], 0, "")

        Local $tagIP_ADDR_STRING = "ptr Next;char IpAddress[16];char IpMask[16];uint Context;"
        $tDnsServersList = DllStructCreate($tagIP_ADDR_STRING, DllStructGetPtr($tBuf) + 268)

        Local $sOutput = $tDnsServersList.IpAddress
        While $tDnsServersList.Next
            $tDnsServersList = DllStructCreate($tagIP_ADDR_STRING, $tDnsServersList.Next)
            $sOutput &= "|" & $tDnsServersList.IpAddress
        WEnd

        Return StringSplit($sOutput, "|", $STR_NOCOUNT)
    Else
        Return SetError(-1, 0, "")
    EndIf
EndFunc   ;==>_GetDnsServerAddress

[LWC]

Thanks! I know it's old, but for anyone looking to pull SRV records, the registry bypass above fails for me too.
So I've revised this and other improvements into a central DNS function.