netdev - Re: [PATCH net-next 0/4] net: mpls: Allow users to configure more labels per route

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: <ef8c79ec-11e2-680b-8be5-c1476bf95a7d@cumulusnetworks.com>
Date:   Tue, 28 Mar 2017 08:39:42 -0600
From:   David Ahern <dsa@...ulusnetworks.com>
To:     "Eric W. Biederman" <ebiederm@...ssion.com>
Cc:     Robert Shearman <rshearma@...cade.com>, netdev@...r.kernel.org,
        roopa@...ulusnetworks.com
Subject: Re: [PATCH net-next 0/4] net: mpls: Allow users to configure more
 labels per route

On 3/27/17 9:08 PM, Eric W. Biederman wrote:
> 
> Overall I like what is being accomplished by this patchset.
> I especially like the fact that the forwarding path is left
> essentially unchanged, and that the struct mpls_route shirnks a little
> for the common case.
> 
> I believe we should just kill MAX_NEW_LABELS.
> 
> I think the only significant change from your patch is the removal of an
> array from mpls_route_config.
> 
> With the removal of MAX_NEW_LABELS I would replace it by a sanity check
> in mpls_rt_alloc that verifies that the amount we are going to allocate
> for struct mpls_route is < PAGE_SIZE.  Anything larger is just
> asking for trouble.

Sure. We would want a consistent API across architectures. As I recall
some of them have 64kB page sizes, so rather than page size let's limit
to the number 4096 rather than PAGE_SIZE.

> 
> That should put our practical limit just a little bit below 32 nexthops
> adding 32 labels each.

I send out a v2 soon.