netdev - Re: [PATCH] net-netlink: Add a new attribute to expose TCLASS values via netlink

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: <20111109.153451.441383099995731023.davem@davemloft.net>
Date:	Wed, 09 Nov 2011 15:34:51 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	zenczykowski@...il.com
Cc:	maze@...gle.com, netdev@...r.kernel.org, muralira@...gle.com,
	shemminger@...tta.com, eric.dumazet@...il.com
Subject: Re: [PATCH] net-netlink: Add a new attribute to expose TCLASS
 values via netlink

From: Maciej Żenczykowski <zenczykowski@...il.com>
Date: Mon,  7 Nov 2011 16:23:11 -0800

> From: Maciej Żenczykowski <maze@...gle.com>
> 
> commit 3ceca749668a52bd795585e0f71c6f0b04814f7b added a TOS attribute.
> 
> Unfortunately TOS and TCLASS are both present in a dual-stack v6 socket,
> furthermore they can have different values.  As such one cannot in a
> sane way expose both through a single attribute.
> 
> Signed-off-by: Maciej Żenczyowski <maze@...gle.com>

I can't see how an ipv6 mapped socket can even set the inet->tos value.

As far as I can see, only net/ipv4/ip_sockglue.c:ip_setsockopt() provides
the interface to change inet->tos.

And ipv6 sockets, of any type, are provided no such vector by which to
get at those interfaces.

So inet->tos is always left at it's default value for ipv6 mapped sockets,
and therefore I see no reason to report TCLASS vs. TOS separately.

In fact, what I would suggest is to do something about the lack of
ability to set inet->tos, and the best way to do that seems to be to
simply propagate the npinfo->tclass setting into inet->tos.  Performaing
any munging if necessary.

I'm not applying this patch.

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html