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  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:	Thu, 27 Sep 2007 08:39:45 -0400
From:	jamal <>
To:	Herbert Xu <>
Cc:	"David S. Miller" <>,,
	Alexey Kuznetsov <>
Subject: Re: [PKT_SCHED]: Add stateless NAT

nice work. I like the egress flag idea;->
and who would have thunk stateless nat could be written in such a few
lines ;-> I would have put the checksum as a separate action but it is
fine the way you did it since it simplifies config.
more comments below.

On Thu, 2007-27-09 at 15:34 +0800, Herbert Xu wrote:

> +config NET_ACT_NAT
> +        tristate "Stateless NAT"
> +        depends on NET_CLS_ACT
> +        select NETFILTER

I am gonna have to agree with Evgeniy on this Herbert;->
The rewards are it will improve performance for people who dont need
Ok, who is gonna move the csum utility functions out? /me looks at
I could do it realsoonnow if noone raises their hands. 
In any case, it would be real nice to have but i dont see it as a show
stopper for inclusion.
> +static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
> +		   struct tcf_result *res)
> +{
> +	struct tcf_nat *p = a->priv;

> +	spin_lock(&p->tcf_lock);
> +
> +	p->tcf_tm.lastuse = jiffies;
> +	old_addr = p->old_addr;
> +	new_addr = p->new_addr;
> +	mask = p->mask;
> +	egress = p->flags & TCA_NAT_FLAG_EGRESS;
> +	action = p->tcf_action;
> +
> +	p->tcf_bstats.bytes += skb->len;
> +	p->tcf_bstats.packets++;
> +
> +	spin_unlock(&p->tcf_lock);

You also need to p->tcf_qstats.drops++ for all packets that get shot.
I would just hold tcf_lock until the end.
If you are concerned about performance of multiple flows contending for
the lock, then just create a new action entry per flow by using a
different index for each; you cant avoid contention with control path in
case of updates, but i suspect that would be a rare occasion.

Do you have plans to do the iproute bits? If you do it will be nice to
also update the doc/examples with some simple example(s).


To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists