netdev - Re: [PATCH 0/2] netem: trace enhancement

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: <47556B20.2030700@trash.net>
Date:	Tue, 04 Dec 2007 15:58:40 +0100
From:	Patrick McHardy <kaber@...sh.net>
To:	Ariane Keller <ariane.keller@....ee.ethz.ch>
CC:	Ben Greear <greearb@...delatech.com>,
	Stephen Hemminger <shemminger@...ux-foundation.org>,
	netdev@...r.kernel.org, herbert@...dor.apana.org.au,
	Rainer Baumann <baumann@....ee.ethz.ch>
Subject: Re: [PATCH 0/2] netem: trace enhancement

Ariane Keller wrote:
> 
>>> That sounds like it would also be possible using rtnetlink. You could
>>> send out a notification whenever you switch the active buffer and have
>>> userspace listen to these and replace the inactive one.
> 
> I guess using rtnetlink is possible. However I'm not sure about how to 
> implement it:
> The first thought was to use RTM_NEWQDISC to send the data to the 
> netem_change() function (similar to tc_qdisc_modify() ).

That sounds reasonable.

> But with this 
> we would need the tcm_handle, tcm_parent arguments etc. which are not 
> known in q_netem.c
> Therefore we would have to change the parse_qopt() function prototype in 
> order to pass the whole "req" and not only the nlmsghdr.

I assume you mean netem_init, parse_qopt is userspace. But I don't
see how that is related, emptying the buffer happens during packet
processing, right?

I guess I would simply change the qdisc_notify function to not
require a struct nlmsghdr * (simply pass nlmsg_seq directly) and
use that to send notifications. The netem dump function would
add the buffer state. BTW, the parent class id is available in
sch->parent, the handle in sch->handle, but qdisc_notify should
take care of everything you need.
--
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