netdev - Re: [B.A.T.M.A.N.] Odd use of %14pM in net/batman-adv/distributed-arp-table.c

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Message-ID: <5300874.nPgxNW8UST@bentobox>
Date:   Wed, 14 Jun 2017 10:23:38 +0200
From:   Sven Eckelmann <sven@...fation.org>
To:     b.a.t.m.a.n@...ts.open-mesh.org
Cc:     Joe Perches <joe@...ches.com>,
        Marek Lindner <mareklindner@...mailbox.ch>,
        Simon Wunderlich <sw@...onwunderlich.de>,
        Antonio Quartulli <a@...table.cc>, netdev@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        linux-kernel@...r.kernel.org
Subject: Re: [B.A.T.M.A.N.] Odd use of %14pM in net/batman-adv/distributed-arp-table.c

On Dienstag, 13. Juni 2017 14:51:41 CEST Joe Perches wrote:
> An output mac address is 17 bytes
[...]
> but in net/batman-adv/distributed-arp-table.c
[...]
> %14pM is odd as this should not emit the last byte of the
> mac address.  So given the example above, it would output
> 00:11:22:33:44
[...]

I completely agree too the "wrong length" part. It is currently not omitting 
the last byte:

    Distributed ARP Table (bat0):
              IPv4             MAC        VID   last-seen
     *   10.204.28.206 e8:50:8b:8b:71:8d   -1      4:05
     *    10.204.77.54 6c:2f:2c:43:70:eb   -1      1:56
     *    10.25.21.138 ec:1f:72:c3:15:51   -1      4:21
     *   10.204.27.220 08:70:45:8c:ac:db   -1      2:32
     *   192.168.42.22 64:66:b3:bb:8e:ef   -1      0:18
     *     10.204.64.1 02:ba:7a:df:04:00   -1      0:00
     *   192.168.42.27 e8:de:27:f9:0f:48   -1      0:32

But it definitely also not "correct". I see something similar in the IV OGM
code:

    net/batman-adv/bat_iv_ogm.c:               "bidirectional: orig = %-15pM neigh = %-15pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, iface_penalty: %3i, total tq: %3i, if_incoming = %s, if_outgoing = %s\n",

Do you want to provide a patch to convert it to simple %pM's?

Kind regards,
	Sven
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