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From: "Timo Teräs" <timo.teras@iki•fi>
To: hadi@cyberus•ca
Cc: Herbert Xu <herbert@gondor•apana.org.au>,
	"David S. Miller" <davem@davemloft•net>,
	Patrick McHardy <kaber@trash•net>,
	netdev@vger•kernel.org
Subject: Re: [RFC] SPD basic actions per netdev
Date: Thu, 01 Apr 2010 15:10:04 +0300	[thread overview]
Message-ID: <4BB48D1C.80205@iki.fi> (raw)
In-Reply-To: <1270123246.26743.177.camel@bigi>

jamal wrote:
> On Thu, 2010-04-01 at 14:47 +0300, Timo Teräs wrote:
> 
>> The thing is that currently FWD 'dev blah' matches the interface
>> to which the packet is being forwarded to. Someone might be using
>> this feature already.
> 
> So this is the part i am missing i think. If i look at:
> 
> int ip_forward(struct sk_buff *skb)
> {
> .....
>         if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb))
>                 goto drop;
> ....
> ........later forwarding happens here ...
>         if (!xfrm4_route_forward(skb))
>                 goto drop;
> ...
> }
> 
> On entry we have a legit skb->skb_iif.
> The validity check is before forwarding decision (where the interface
> the packet is being forwarded to is recognized).

On entry to ip_forward the routing decision has already been made.
Both oif and iif are valid on entry.

Currently policy_check() uses oif for SPD matching.

Do note that xfrm4_route_forward() is a no-op if there's no matching
policy. It has nothing to do with routing decision, it's purpose
is to wrap the dst_entry with xfrm_dst if the flow matches a valid
SPD.

>> Your patch changes semantics on how FWD policies are matched.
> 
> I agree if what you say earlier is true.


  reply	other threads:[~2010-04-01 12:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-31 16:37 [RFC] SPD basic actions per netdev jamal
2010-03-31 22:58 ` jamal
2010-04-01  0:33 ` Herbert Xu
2010-04-01  2:35   ` jamal
2010-04-01  2:52     ` Herbert Xu
2010-04-01  4:52       ` Timo Teräs
2010-04-01  6:01         ` Herbert Xu
2010-04-01  6:20           ` Timo Teräs
2010-04-01  6:28             ` Herbert Xu
2010-04-01  6:32               ` Timo Teräs
2010-04-01  6:39                 ` Herbert Xu
2010-04-01 11:29                   ` jamal
2010-04-01 11:47                     ` Timo Teräs
2010-04-01 12:00                       ` jamal
2010-04-01 12:10                         ` Timo Teräs [this message]
2010-04-01 12:34                           ` jamal

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