netdev - Re: [PATCH] can: j1939: convert PGN structure to a table

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] [day] [month] [year] [list]

Message-ID: <4ca7cb3c-554c-7fcd-8d8f-369fce222c5a@pengutronix.de>
Date:   Tue, 27 Oct 2020 13:15:45 +0100
From:   Marc Kleine-Budde <mkl@...gutronix.de>
To:     Yegor Yefremov <yegorslists@...glemail.com>,
        linux-can@...r.kernel.org, netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH] can: j1939: convert PGN structure to a table

On 10/27/20 12:27 PM, Yegor Yefremov wrote:
>>> Can you add a row description that indicated that these numbers are. They are
>>> probably bit positions within the CAN-ID?
>>
>> This is true for up to 99.9%, depending on who you ask.
>> this maps indeed to the bit positions in the CAN-ID, as in J1939-21.
>> The trouble is that PGN's are also communicated as such in the payload,
>> e.g. in the TP and ETP (see J1939-81 if i remember correctly).
>> Since only PGN is written there, without SA, the bit position relative
>> to the CAN-ID are ... making things look fuzzy.
>>
>> So I the best I can propose is to add a 2nd row :-)

Sounds reasonable.

> I have sent v2. Should I also include the tables for PDU1 and PDU2
> formats as well as the general table with ID and Data? See Wiki [1]

Make it so.

> [1] https://de.wikipedia.org/wiki/SAE_J1939#/media/Datei:J1939_Aufsplittung_CAN-Identifier.png

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |



Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)