netdev - Re: Re: why do we need printk on sending syn flood cookie?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <23001280765498@web50.yandex.ru>
Date:	Mon, 02 Aug 2010 20:11:36 +0400
From:	Franchoze Eric <franchoze@...dex.ru>
To:	Florian Westphal <fw@...len.de>
Cc:	netdev@...r.kernel.org
Subject: Re: Re: why do we need printk on sending syn flood cookie?



02.08.10, 12:17, "Florian Westphal" <fw@...len.de>:

> Franchoze Eric  wrote:
>  >  Just sirious why do we need printk each 1 second (60*HZ) about possible syn-flood? It really floods dmesg. Is there something dengerous? I have suggestion to turn off printk about sending tcp cookie each 1 second.
>  
>  It is handled exactly like other printks in the networking path,
>  e.g. receipt of tcp wscale == 15.
>  
>  Why does this need special treatment?
>  

For now I see "possible SYN flooding on port %d. Sending cookies.\n" message each second on my server. I know that there are a lot of SYNs and I know that kernel sends cookie. Why do I need so mach printk?
So I suggested add new value to /proc/sys/net/ipv4/tcp_syncookies, which will enable cookie but this printk will be turned off.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html