Re: ICMP socket with Gambas

[vuott@xxxxxxxxxxxx]

Uhmmm... sorry, correct structure is:

Public Struct SockAddr 
  SinFamily As SHORT  SinPort As SHORT  SinAddr As Pointer
End Struct

(with SHORT, not Integer)



28 giu 2025, 14:38 da :

> ...try:
>
> [code]
>
> Library "libc:6"
>
> Private Enum IPPROTO_IP, IPPROTO_ICMP, AF_INET, SOCK_DGRAM = 2, SOCK_RAW, IP_HDRINCL = 3, IPPROTO_TCP = 6
>
> Public Struct SockAddr 
>   SinFamily As Integer
>   SinPort As Integer
>   SinAddr As Pointer
> End Struct
>
> Private Extern socket(domain As Integer, type As Integer, protocol As Integer) As Integer
> Private Extern close(sockfd As Integer) As Integer
> Private Extern inet_pton(af As Integer, src As String, dst As Pointer) As Integer
> Private Extern sendto(sockfd As Integer, buf As Byte[], size As Integer, flags As Integer, sockaddr As SockAddr, addrlen As Integer) As Integer
>
> Private Sub CalcChecksum(aHeader As Byte[]) As Short
>   
>   Dim iSum As Long
>   Dim iVal As Short
>   
>   For i As Integer = 0 To aHeader.Max Step 2
>     iVal = (CShort(aHeader[i]) Lsl 8) + aHeader[i + 1]
>     iSum += iVal
>   Next
>   
>   While iSum > &HFFFF&
>     iSum = (iSum Lsr 16) + (iSum And &HFFFF)
>   Wend
>   
>   Return Not iSum
>   
> End
>
> Public Sub Main()
>
>   Dim sockfd, rc As Integer
>   Dim aHeader As Short[] = [8, 0, 0, 0, 0, 0, 0, 0]
>   Dim iChecksum As Short
>   Dim DestAddr As New SockAddr
>   
>   sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP)
>   If sockfd < 0 Then 'error
>     Print "Socket call error: " & System.Error
>     Quit 
>   Endif
>
>   DestAddr.SinFamily = AF_INET
>   DestAddr.SinPort = 0
>   Dim p As Pointer = DestAddr.SinAddr
>   rc = inet_pton(AF_INET, "8.8.8.8", VarPtr(p))
>   If rc < 1 Then 
>     Print "Error converting address."
>     Quit 
>   Endif
>
>   iChecksum = CalcChecksum(aHeader)
>   aHeader[2] = (iChecksum Lsr 8) And &HFF
>   aHeader[3] = iChecksum And &HFF
>
>   rc = sendto(sockfd, aHeader, 8, 0, DestAddr, Object.SizeOf(DestAddr))
>   If rc < 0 Then 
>     Print "Send error:", System.Error
>   Else 
>     Print "Bytes sent:", rc
>   Endif
>
>   Finally 
>     If sockfd Then 
>       rc = close(sockfd)
>     Endif
>     If rc < 0 Then  'error
>       Print "Close error: " & System.Error
>     Endif
>     
>     Catch 
>       Debug Error.Text;; "at";; Error.Where
>
> End
>
> [/code]
>
>
>
>
>
>
> 28 giu 2025, 00:05 da t.lee.davidson@xxxxxxxxx:
>
>> On 6/27/25 2:03 PM, Linus wrote:
>>
>>> Hello Lee,
>>>
>>> Thank you for your comment and research and yes I knew about the need to be root to run the code.
>>> A lot a network command on Linux require the ‘root’ access but I was not aware about the SOCK_DGRAM option.
>>>
>>> Unfortunately, in the end, for now, no way to do an ICMP request in Gambas…
>>>
>>> I will wait the answer from Benoit, about if is possible to do something on this way.
>>>
>>> Olivier
>>>
>>
>> I created a test project using the libc:6 shared library for creating a socket and sending a ping echo request.
>>
>> Wireshark confirms that the 'ping_cmd' executable does indeed send the request, but the attached project does not even though I get no errors from the libc function calls.
>>
>> I figure I must be doing something wrong as I am not strong on external functions with structures and pointers.
>>
>>
>> --
>> Lee
>>
>> --- Gambas User List Netiquette [https://gambaswiki.org/wiki/doc/netiquette] ----
>> --- Gambas User List Archive [https://lists.gambas-basic.org/archive/user] ----
>>
>
>