netdev - Re: [PATCH net-next v5 2/2] openvswitch: Support conntrack zone limit

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]

Date:   Fri, 25 May 2018 11:38:58 -0700
From:   Pravin Shelar <pshelar@....org>
To:     Yi-Hung Wei <yihung.wei@...il.com>
Cc:     Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next v5 2/2] openvswitch: Support conntrack zone limit

On Thu, May 24, 2018 at 5:56 PM, Yi-Hung Wei <yihung.wei@...il.com> wrote:
> Currently, nf_conntrack_max is used to limit the maximum number of
> conntrack entries in the conntrack table for every network namespace.
> For the VMs and containers that reside in the same namespace,
> they share the same conntrack table, and the total # of conntrack entries
> for all the VMs and containers are limited by nf_conntrack_max.  In this
> case, if one of the VM/container abuses the usage the conntrack entries,
> it blocks the others from committing valid conntrack entries into the
> conntrack table.  Even if we can possibly put the VM in different network
> namespace, the current nf_conntrack_max configuration is kind of rigid
> that we cannot limit different VM/container to have different # conntrack
> entries.
>
> To address the aforementioned issue, this patch proposes to have a
> fine-grained mechanism that could further limit the # of conntrack entries
> per-zone.  For example, we can designate different zone to different VM,
> and set conntrack limit to each zone.  By providing this isolation, a
> mis-behaved VM only consumes the conntrack entries in its own zone, and
> it will not influence other well-behaved VMs.  Moreover, the users can
> set various conntrack limit to different zone based on their preference.
>
> The proposed implementation utilizes Netfilter's nf_conncount backend
> to count the number of connections in a particular zone.  If the number of
> connection is above a configured limitation, ovs will return ENOMEM to the
> userspace.  If userspace does not configure the zone limit, the limit
> defaults to zero that is no limitation, which is backward compatible to
> the behavior without this patch.
>
> The following high leve APIs are provided to the userspace:
>   - OVS_CT_LIMIT_CMD_SET:
>     * set default connection limit for all zones
>     * set the connection limit for a particular zone
>   - OVS_CT_LIMIT_CMD_DEL:
>     * remove the connection limit for a particular zone
>   - OVS_CT_LIMIT_CMD_GET:
>     * get the default connection limit for all zones
>     * get the connection limit for a particular zone
>
> Signed-off-by: Yi-Hung Wei <yihung.wei@...il.com>

Thanks for working on the feature.

Acked-by: Pravin B Shelar <pshelar@....org>