netdev - Re: [PATCH] act_mirred: don't clone skb when skb isn't shared

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]

Date:	Sat, 05 Jun 2010 08:53:55 -0400
From:	jamal <hadi@...erus.ca>
To:	Changli Gao <xiaosuo@...il.com>
Cc:	"David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: Re: [PATCH] act_mirred: don't clone skb when skb isn't shared

On Fri, 2010-06-04 at 21:43 +0800, Changli Gao wrote:
> don't clone skb when skb isn't shared
> 
> When the tcf_action is TC_ACT_STOLEN, and the skb isn't shared, we don't need
> to clone a new skb. As the skb will be freed after this function returns, we
> can use it freely once we get a reference to it.

It looks like a good optimization - but i am not a big fan of one-offs
[because usability goes down and I am forced to explain it longer in the
rules (refer to: Documentation/networking/tc-actions-env-rules.txt)]

How about you update skb_act_clone to take take the action code as well
and do the check the if stolen/queued it does a skb_get otherwise it
calls skb_clone?

cheers,
jamal

--
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