Check an IP in a network range

[Apzo]

Hello

_IPInRange("192.168.10.12", "192.168.10.8/29")

will tell you if 192.168.10.12 is in 192.168.10.8/29 for example.

It uses CIDR notation (more details about CIDR notation here).

Can be usefull when you want to add net control into your scripts

Apzo.

expandcollapse popup

;~ function _IPRange() : checks if a given IP address is a given network (CIDR notation)
;~ $IP : 192.168.10.12 for example. Must be valid.
;~ $CIDR : 192.168.10.8/29 for example. Google CIDR or see http://www.pantz.org/networking/tcpip/subnetchart.shtml
;~ Return : true if $IP in $CIDR, false if not, sets @error if something wrong.

Func _IPInRange($IP, $CIDR)
    Local $T = StringSplit($CIDR, "/")
    If @error Then
        SetError(1)
        Return false
    EndIf
    If $T[0] <> 2 Then
        SetError(2)
        Return false
    EndIf
    If Not _IsIP($IP) Then
        SetError(7)
        Return false
    EndIf
    If Not _IsIP($T[1]) Then
        SetError(7)
        Return false
    EndIf
    If $T[2] = 0 Then Return True
    Local $NETSTART = _IPToInt($T[1])
    If @error Then
        SetError(3)
        Return false
    EndIf
    Local $BITMASK = 32 - $T[2]
    $NETSTART = BitShift($NETSTART, $BITMASK)
    $IP = _IPToInt($IP)
    $IP = BitShift($IP, $BITMASK)
    If @error Then
        SetError(4)
        Return false
    EndIf
    If $IP = $NETSTART Then Return true
    Return false
EndFunc

;~ function _IPToInt() : converts a quad dotted IP into an integer for further comparison.
;~ $IP : quad dotted notation. Ex : 192.168.10.12
;~ Return : according integer if OK or sets @error
Func _IPToInt($IP)
    If Not _IsIP($IP) Then
        SetError(7)
        Return false
    EndIf
    Local $I = StringSplit($IP, ".")
    If @error Then
        SetError(5)
        Return 0
    EndIf
    Return BitShift($I[1], -12) + BitShift($I[2], -8) + BitShift($I[3], -4) + $I[4]
EndFunc

;~ Checks if $IP is [0-255].[0-255].[0-255].[0-255] style
Func _IsIP($IP)
    Local $T = StringSPlit($IP, ".")
    If $T[0] <> 4 Then Return false
    If Not StringIsInt($T[1]) Then Return false
    If Not StringIsInt($T[2]) Then Return false
    If Not StringIsInt($T[3]) Then Return false
    If Not StringIsInt($T[4]) Then Return false
    If $T[1] < 0 Or $T[1] > 255 Then Return false
    If $T[2] < 0 Or $T[2] > 255 Then Return false
    If $T[3] < 0 Or $T[3] > 255 Then Return false
    If $T[4] < 0 Or $T[4] > 255 Then Return false
    Return true
EndFunc

[Schlumpf]

it don't works for me... please make a samplescript

[nitekram]

it don't works for me... please make a samplescript

The example that was given should work - copy everything in the code box and then add this to the top.

$test = _IPInRange("192.168.10.12", "192.168.10.8/29")

msgbox('','0',$test)

[ConsultingJoe]

It worked for me but I dont quite understand, what is the range of 8/29?

[/dev/null]

It worked for me but I dont quite understand, what is the range of 8/29?

http://jodies.de/ipcalc?host=192.168.10.8&...1=29&mask2=

Cheers

Kurt

[ConsultingJoe]

http://jodies.de/ipcalc?host=192.168.10.8&...1=29&mask2=

Cheers

Kurt

yeah but what is this used for?

[/dev/null]

yeah but what is this used for?

erm, networking... you know the tcp/ip stuff and the like... ???

EDIT: O.K. I guess you don't know the concept of subnetting, right? Then read this:

http://en.wikipedia.org/wiki/Subnetting

Cheers

Kurt

Edited November 11, 2006 by /dev/null

[Apzo]

My apologies, I didn't even gave a sample script

The one from nitekram is good, thanks !

So this is a more complex (and useful) example, allowing connexion only from local addresses.

Global $sock

While 1
    $sock = TCPAccept("0.0.0.0")
    If $sock >= 0 Then
        If _IPInRange(SocketToIP($sock), "129.168.0.0/16") Then
            Local $recv= TCPRecv($sock, 2048)
            ;~ do some stuff with $recv
        EndIf
    EndIf
    TCPCloseSocket($sock)
Wend


Func SocketToIP($SHOCKET)
    Local $sockaddr = DLLStructCreate("short;ushort;uint;char[8]")
    Local $aRet = DLLCall("Ws2_32.dll","int","getpeername","int",$SHOCKET, _
            "ptr",DLLStructGetPtr($sockaddr),"int_ptr",DLLStructGetSize($sockaddr))
    If Not @error And $aRet[0] = 0 Then
        $aRet = DLLCall("Ws2_32.dll","str","inet_ntoa","int",DLLStructGetData($sockaddr,3))
        If Not @error Then $aRet = $aRet[0]
    Else
        $aRet = 0
    EndIf
    $sockaddr = 0
    Return $aRet
EndFunc

This way, the socket is closed if not in the range 192.168.0.0/16, aka 192.168.0.0 netmask 255.255.0.0

If in range, TcpRecv will be performed.

Apzo.

[newcoder]

This script was submitted a couple of years ago and looks great, but I'm finding its accuracy to be off a bit and its been way too long since doing any bitshift's to figure out why.

The test will show True for addresses in the scope, but also returns true for items outside that should be False. The following should be False as the IP is outside of the scope 192.168.2.0-192.168.2.255

$test = _IPInRange("192.168.1.105", "192.168.2.0/24")

Tests with some smaller subnets such as /29 seemed to work, but /25 and larger subnets failed. Does anyone know where the error is in this script or know of another way to determine if an IP is within a certain range?

[SkinnyWhiteGuy]

Kinda an old topic, but I took a quick look at it (BitWise operators get me every time). I think the problem was in this _IPToInt() function. He was only shifting the bytes (which are 8 bits each) 4 bits, so he was mixing stuff up that shouldn't be mixed. He was also just adding them, which normally is fine, but BitOR is a better way to do it, and will make sure the other bit shifts play nice as well.

Here's the corrected version, which makes your above test show False, as it should.

Func _IPToInt($IP)
    If Not _IsIP($IP) Then
        SetError(7)
        Return false
    EndIf
    Local $I = StringSplit($IP, ".")
    If @error Then
        SetError(5)
        Return 0
    EndIf
    Return BitOR(BitShift($I[1], -24), BitShift($I[2], -16), BitShift($I[3], -8), $I[4])
EndFunc

[newcoder]

Here's the corrected version, which makes your above test show False, as it should.

Outstanding - works great. Thanks.