netdev - Re: [PATCH v5 net] net, ip6_tunnel: enhance tunnel locate with link check

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: <13b0e28f-136f-0a16-8900-784afcad549d@6wind.com>
Date:   Fri, 14 Feb 2020 10:50:31 +0100
From:   Nicolas Dichtel <nicolas.dichtel@...nd.com>
To:     William Dauchy <w.dauchy@...teo.com>, netdev@...r.kernel.org
Subject: Re: [PATCH v5 net] net, ip6_tunnel: enhance tunnel locate with link
 check

Le 13/02/2020 à 18:19, William Dauchy a écrit :
> With ipip, it is possible to create an extra interface explicitly
> attached to a given physical interface:
> 
>   # ip link show tunl0
>   4: tunl0@...E: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default qlen 1000
>     link/ipip 0.0.0.0 brd 0.0.0.0
>   # ip link add tunl1 type ipip dev eth0
>   # ip link show tunl1
>   6: tunl1@...0: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default qlen 1000
>     link/ipip 0.0.0.0 brd 0.0.0.0
> 
> But it is not possible with ip6tnl:
> 
>   # ip link show ip6tnl0
>   5: ip6tnl0@...E: <NOARP> mtu 1452 qdisc noop state DOWN mode DEFAULT group default qlen 1000
>       link/tunnel6 :: brd ::
>   # ip link add ip6tnl1 type ip6tnl dev eth0
>   RTNETLINK answers: File exists
> 
> This patch aims to make it possible by adding link comparaison in both
> tunnel locate and lookup functions; we also modify mtu calculation when
> attached to an interface with a lower mtu.
> 
> This permits to make use of x-netns communication by moving the newly
> created tunnel in a given netns.
> 
> Signed-off-by: William Dauchy <w.dauchy@...teo.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@...nd.com>