netdev - Re: [PATCH net-next] icmp: add a global rate limitation

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 for Android: free password hash cracker in your pocket

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

Date:	Tue, 23 Sep 2014 12:48:07 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	netdev@...r.kernel.org
Subject: Re: [PATCH net-next] icmp: add a global rate limitation

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Fri, 19 Sep 2014 07:38:40 -0700

> From: Eric Dumazet <edumazet@...gle.com>
> 
> Current ICMP rate limiting uses inetpeer cache, which is an RBL tree
> protected by a lock, meaning that hosts can be stuck hard if all cpus
> want to check ICMP limits.
> 
> When say a DNS or NTP server process is restarted, inetpeer tree grows
> quick and machine comes to its knees.
> 
> iptables can not help because the bottleneck happens before ICMP
> messages are even cooked and sent.
> 
> This patch adds a new global limitation, using a token bucket filter,
> controlled by two new sysctl :
> 
> icmp_msgs_per_sec - INTEGER
>     Limit maximal number of ICMP packets sent per second from this host.
>     Only messages whose type matches icmp_ratemask are
>     controlled by this limit.
>     Default: 1000
> 
> icmp_msgs_burst - INTEGER
>     icmp_msgs_per_sec controls number of ICMP packets sent per second,
>     while icmp_msgs_burst controls the burst size of these packets.
>     Default: 50
> 
> Note that if we really want to send millions of ICMP messages per
> second, we might extend idea and infra added in commit 04ca6973f7c1a
> ("ip: make IP identifiers less predictable") :
> add a token bucket in the ip_idents hash and no longer rely on inetpeer.
> 
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Applied.
--
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