netdev - Re: [PATCH net-next v2] gtp: add notification mechanism

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

Date:   Tue, 25 Aug 2020 19:01:09 +0200
From:   Harald Welte <laforge@...monks.org>
To:     Nicolas Dichtel <nicolas.dichtel@...nd.com>
Cc:     davem@...emloft.net, kuba@...nel.org, pablo@...filter.org,
        osmocom-net-gprs@...ts.osmocom.org, netdev@...r.kernel.org,
        Gabriel Ganne <gabriel.ganne@...nd.com>
Subject: Re: [PATCH net-next v2] gtp: add notification mechanism

Hi Nicolas,

thanks a lot for your patch.

On Tue, Aug 25, 2020 at 05:57:15PM +0200, Nicolas Dichtel wrote:
> Like all other network functions, let's notify gtp context on creation and
> deletion.

While this may be in-line with typical kernel tunnel device practises, I am not
convinced it is the right way to go for GTP.

Contrary to other tunneling mechansims, GTP doesn't have a 1:1 rlationship between
tunnels and netdev's.  You can easily have tens of thousands - or even many more -
PDP contexts (at least one per subscriber) within one "gtp0" netdev.  Also, the state
is highly volatile.  Every time a subscriber registers/deregisters, goes in or out of
coverage, in or out of airplane mode, etc. those PDP contexts go up and down.

Sending (unsolicited) notifications about all of those seems quite heavyweight to me.

-- 
- Harald Welte <laforge@...monks.org>           http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)