netdev - Re: [net 3/3] can: isotp: add SF_BROADCAST support for functional addressing

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: <20201204194435.0d4ab3fd@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com>
Date:   Fri, 4 Dec 2020 19:44:35 -0800
From:   Jakub Kicinski <kuba@...nel.org>
To:     Marc Kleine-Budde <mkl@...gutronix.de>
Cc:     netdev@...r.kernel.org, davem@...emloft.net,
        linux-can@...r.kernel.org, kernel@...gutronix.de,
        Oliver Hartkopp <socketcan@...tkopp.net>,
        Thomas Wagner <thwa1@....de>
Subject: Re: [net 3/3] can: isotp: add SF_BROADCAST support for functional
 addressing

On Fri,  4 Dec 2020 14:35:08 +0100 Marc Kleine-Budde wrote:
> From: Oliver Hartkopp <socketcan@...tkopp.net>
> 
> When CAN_ISOTP_SF_BROADCAST is set in the CAN_ISOTP_OPTS flags the CAN_ISOTP
> socket is switched into functional addressing mode, where only single frame
> (SF) protocol data units can be send on the specified CAN interface and the
> given tp.tx_id after bind().
> 
> In opposite to normal and extended addressing this socket does not register a
> CAN-ID for reception which would be needed for a 1-to-1 ISOTP connection with a
> segmented bi-directional data transfer.
> 
> Sending SFs on this socket is therefore a TX-only 'broadcast' operation.

Unclear from this patch what is getting fixed. Looks a little bit like
a feature which could be added in a backward compatible way, no?
Is it only added for completeness of the ISOTP implementation?