Autoit TCP functions: use of "non-blocking-ports" possible?

[rudi]

Hi Devs.

As in General Help & Support I couldn't get advices to get rid of the quite long timeout period, that seems to be typical for the Windows System (not Autoit, other tools behave the same), I asked in the Novell Chat Forum, if someone knows a solution.

Hamish wrote these lines. This code is really nice and fast.

As I have no clue at all, how much work it might be to implement this for the Autoit Network Functions, I'd like to hear what you developers think about this approach, befor I'm going to submit a feature request.

Regards, Rudi.

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From: "Haitch" <hamish@haitch.net>
Subject: Re: Does anybody know a "Single-EXE" command line port scanner?
Date: Wed, 19 Dec 2012 00:33:46 GMT
Message-ID: <KX7As.1787$go3.1@kovat.provo.novell.com>
Lines: 116

On 12/18/2012 8:15 AM, Rudolf Thilo wrote:

>Hi Hamish,
>
>I'm wondering, whether I should drop a feature request at the
>developers forum of Autoit, to implement "non-blocking sockets" as
>well. As I have no clue, how you did that trick: Would you mind to
>share the source, so that I could point them to your code to see, how
>it's done / how much work this might be?

The code is quick and dirty, but you/they are welcome to it. It's below, in it's entirety, at the end of this post.

>One feature that might be nice would be the option to specify the
>protocol as well, e.g. UDP:69, or icmpv4:8 [1 -> PING]

UDP I could add fairly easily, icmp would require using raw sockets (which I've no idea on and no references to look at, but will see what I can find), or possibly do-able using the icmp.dll - I'll look into it when I have time.

>But this is just an idea, not something I currently need (and,
>honestly, I have no clue at all, how much work these features might be)

H.

program chkPort;
// Input: chkport-ip <ip address> <port> [timeout]
// Output: Text message + Errorlevel
// 0 if we connect,
// 1 if we timeout,
// 2 if we get a socket failure,
// 3 for an invalid address.

uses sockets,inetaux,strutils,winsock2,sysutils;
var
ConSock  : LongInt;
sAddr    : TInetSockAddr;
timeout : dword;
result : boolean;

procedure setnonblockingsocket( s : integer );
var
nb : dword;
begin
nb := 1; // 1 = nonblocking, 0 = blocking
winsock2.ioctlsocket( s , FIONBIO , @nb );
end;

function is_writable_socket( sck : integer; timeout : dword ) : boolean;
var
fds : tfdset;
tv : timeval;
result : boolean;
begin
fd_zero( fds );
fd_set( sck , fds );
tv.tv_sec := timeout div 1000;
tv.tv_usec := timeout mod 1000;

// select (socket+1 , read , write , except , timeout) - wait
// "timeout" to see if data can be written to "socket" without
// blocking

result := select( sck + 1 , nil , @fds , nil , @tv ) > 0;
is_writable_socket := result;
end;

begin
// create a socket, die if we fail
ConSock := Socket(af_inet, sock_stream, 0);
if ConSock = -1 then begin
writeln('Could not open socket: ');
halt(2);
end
else begin

// make it non-blocking
SetNonBlockingSocket(ConSock);

// if timeout defined use it, otherwise default to 2 secs
If paramcount >= 3 then Timeout := numb2dec(paramstr(3),10)
else timeout := 2000;

// fill in the socket info - protocol, address, port
with sAddr do begin
     Family := af_inet;
     Port := htons(numb2dec(paramstr(2),10));
     Addr := StrToAddr(paramstr(1));
     end;

// die if we can't turn the address into something useable
If saddr.Addr = 0 then begin
writeln('Could not resolve ',paramstr(1));
halt(3);
end;

// otherwise try to connect
Result := (fpConnect(ConSock, @sAddr, sizeof(sAddr)) = 0);

// and see if it become writeable in the time allowed
result := result or is_writable_socket(consock, timeout);

// close the socket
Shutdown(ConSock, 2);

// and report results
If result then writeln('Port listening')
else begin
Writeln('Port not listening');
halt(1);
end;
end;
end.