Mailinglist Archive: proxy-suite (11 mails)

[Marius Tomaschewski <mt@xxxxxxx>]

On Fri, Jul 21, 2000 at 12:25:28PM +0200, Lukas Zapletal wrote:
> Sometimes ftp-proxy (transparent version) logs me off the server. In the log
> i have found several messages:
> 
> ftp-proxy [17506] <07/21-12:23:16> USER-ERR reject: '172.20.1.206'
> (ForkLimit 40)
> 
> What it means? I didn`t set any limit and user from 206 was only scanning
> ports on our sever...

Add i.e. "ForkLimit 128" to the /etc/proxy-suite/ftp-proxy.conf.
It's an undocumented feature.... see also MaxClients (default=64).

 ==> ftp-daemon.c:

#define MAX_FORKS       40      /* Default fork-resource-limit  */

/*
** Check whether to limit the number of incoming
** client connections per minute. Use half values
** each to avoid "neighborhood effects". This is
** effectively a Denial of Service prevention.
*/
if ((cnt = config_int(NULL, "ForkLimit", MAX_FORKS)) > 0) {
        slice = time(NULL) / (FORK_INTERVAL / 2);
        if (slice != last_slice) {
                last_slice = slice;
                last_count = 0;
        }
        if (++last_count >= (cnt / 2)) {
                close(sock);
                syslog_write(U_ERR,
                        "reject: '%s' (ForkLimit %d)",
                        peer, cnt);
                return;
        }
}

Regards,
 Marius Tomaschewski <mt@xxxxxxx>
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