[1/4] [IPV6]: Remove redundant length check on input

[1/4] [IPV6]: Remove redundant length check on input

[Herbert Xu]

Hi Dave:

I've added GSO for TCPv6 and updated Ananda's patch.  Please note that
the following patches have only been compile-tested.

[IPV6]: Remove redundant length check on input

We don't need to check skb->len when we're just about to call
pskb_may_pull since that checks it for us.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Cheers,
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Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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--
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -84,14 +84,9 @@ int ipv6_rcv(struct sk_buff *skb, struct
 	 */
 	IP6CB(skb)->iif = skb->dst ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex;
 
-	if (skb->len < sizeof(struct ipv6hdr))
+	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
 		goto err;
 
-	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
-		goto drop;
-	}
-
 	hdr = skb->nh.ipv6h;
 
 	if (hdr->version != 6)

Re: [1/4] [IPV6]: Remove redundant length check on input

[YOSHIFUJI Hideaki / 吉藤英明]

In article <20060630054209.GA28558@gondor.apana.org.au> (at Fri, 30 Jun 2006 15:42:09 +1000), Herbert Xu <herbert@gondor.apana.org.au> says:

> [IPV6]: Remove redundant length check on input
> 
> We don't need to check skb->len when we're just about to call
> pskb_may_pull since that checks it for us.
> 
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

-- 
YOSHIFUJI Hideaki @ USAGI Project  <yoshfuji@linux-ipv6.org>
GPG-FP  : 9022 65EB 1ECF 3AD1 0BDF  80D8 4807 F894 E062 0EEA

Re: [1/4] [IPV6]: Remove redundant length check on input

[David Miller]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 30 Jun 2006 15:42:09 +1000

> I've added GSO for TCPv6 and updated Ananda's patch.  Please note that
> the following patches have only been compile-tested.

I applied this and pushed it to Linus, let's cross our fingers :)

RE: [1/4] [IPV6]: Remove redundant length check on input

[Ananda Raju]

Hi, 

I tested the patch, and TSO over ipv6 is working fine. But TSO disable
not working for IPv6. 

I tried the from tree /pub/scm/linux/kernel/git/davem/net-2.6

Ananda 

-----Original Message-----
From: David Miller [mailto:davem@davemloft.net] 
Sent: Friday, June 30, 2006 2:20 PM
To: herbert@gondor.apana.org.au
Cc: Ananda Raju; netdev@vger.kernel.org
Subject: Re: [1/4] [IPV6]: Remove redundant length check on input

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 30 Jun 2006 15:42:09 +1000

> I've added GSO for TCPv6 and updated Ananda's patch.  Please note that
> the following patches have only been compile-tested.

I applied this and pushed it to Linus, let's cross our fingers :)

RE: [1/4] [IPV6]: Remove redundant length check on input

[Michael Chan]

On Fri, 2006-06-30 at 19:44 -0400, Ananda Raju wrote:
> Hi, 
> 
> I tested the patch, and TSO over ipv6 is working fine. But TSO disable
> not working for IPv6. 
> 
You need to clear NETIF_F_TSO6 in dev->features to disable ipv6 TSO.

RE: [1/4] [IPV6]: Remove redundant length check on input

[Ananda Raju]

True, I am referring to "ethtool -K ethX tso off"
ethtool_op_set_tso() won't clear NETIF_F_TSO6 for ethtool -K ethX tso
off

Ananda 
-----Original Message-----
From: Michael Chan [mailto:mchan@broadcom.com] 
Sent: Friday, June 30, 2006 4:53 PM
To: Ananda Raju
Cc: David Miller; herbert@gondor.apana.org.au; netdev@vger.kernel.org
Subject: RE: [1/4] [IPV6]: Remove redundant length check on input

On Fri, 2006-06-30 at 19:44 -0400, Ananda Raju wrote:
> Hi, 
> 
> I tested the patch, and TSO over ipv6 is working fine. But TSO disable
> not working for IPv6. 
> 
You need to clear NETIF_F_TSO6 in dev->features to disable ipv6 TSO.

RE: [1/4] [IPV6]: Remove redundant length check on input

[Michael Chan]

On Fri, 2006-06-30 at 19:55 -0400, Ananda Raju wrote:
> True, I am referring to "ethtool -K ethX tso off"
> ethtool_op_set_tso() won't clear NETIF_F_TSO6 for ethtool -K ethX tso
> off
> 
Instead of using ethtool_op_set_tso() in your ethtool_ops structure, you
can use a private function to set or clear any new bits such as
NETIF_F_TSO6 or NETIF_F_TSO_ECN.

RE: [1/4] [IPV6]: Remove redundant length check on input

[Ananda Raju]

Sure, we will do that. 

-----Original Message-----
From: Michael Chan [mailto:mchan@broadcom.com] 
Sent: Friday, June 30, 2006 5:08 PM
To: Ananda Raju
Cc: David Miller; herbert@gondor.apana.org.au; netdev@vger.kernel.org
Subject: RE: [1/4] [IPV6]: Remove redundant length check on input

On Fri, 2006-06-30 at 19:55 -0400, Ananda Raju wrote:
> True, I am referring to "ethtool -K ethX tso off"
> ethtool_op_set_tso() won't clear NETIF_F_TSO6 for ethtool -K ethX tso
> off
> 
Instead of using ethtool_op_set_tso() in your ethtool_ops structure, you
can use a private function to set or clear any new bits such as
NETIF_F_TSO6 or NETIF_F_TSO_ECN.

Re: [1/4] [IPV6]: Remove redundant length check on input

[Herbert Xu]

On Fri, Jun 30, 2006 at 07:44:49PM -0400, Ananda Raju wrote:
> 
> I tested the patch, and TSO over ipv6 is working fine. But TSO disable
> not working for IPv6. 
> 
> I tried the from tree /pub/scm/linux/kernel/git/davem/net-2.6

I think we need some new ethtool helper functions that sets/clears both
TSO/TSO6.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [1/4] [IPV6]: Remove redundant length check on input

[David Miller]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Sat, 1 Jul 2006 13:39:39 +1000

> On Fri, Jun 30, 2006 at 07:44:49PM -0400, Ananda Raju wrote:
> > 
> > I tested the patch, and TSO over ipv6 is working fine. But TSO disable
> > not working for IPv6. 
> > 
> > I tried the from tree /pub/scm/linux/kernel/git/davem/net-2.6
> 
> I think we need some new ethtool helper functions that sets/clears both
> TSO/TSO6.

Do you really want to semantically seperate TSO and TSO6?

I would think that real users who want to disable TSO, wish
to do so unilaterally.

I think we should only add the TSO6 specific knob if we find
through experience that it often comes up that someone wants
to just disable ipv6 vs. ipv4 TSO.

Re: [1/4] [IPV6]: Remove redundant length check on input

[Herbert Xu]

On Mon, Jul 03, 2006 at 07:44:06PM -0700, David Miller wrote:
>
> > I think we need some new ethtool helper functions that sets/clears both
> > TSO/TSO6.
> 
> Do you really want to semantically seperate TSO and TSO6?
> 
> I would think that real users who want to disable TSO, wish
> to do so unilaterally.

That's what I meant.  I meant ethtool helper functions that
clear and set both TSO/TSO6 flags at the same time.

Alternatively, we can add a new features bit which gives the inherent
features of a device.  That can then be used to derive the actual
features in use.  That way we won't need to invent a new ethtool
helper function for this.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [1/4] [IPV6]: Remove redundant length check on input

[Herbert Xu]

On Tue, Jul 04, 2006 at 12:45:27PM +1000, herbert wrote:
> 
> That's what I meant.  I meant ethtool helper functions that
> clear and set both TSO/TSO6 flags at the same time.

I think I was a bit ambiguous here.  To expand on my argument, what
I'm saying is that we can't just change the existing ethtool helper
functions to set TSO6 since that'd break NICs which do not support
TSO6.

Instead of adding an ad-hoc ethtool function in the neterion driver,
we should either add a new ethtool function which sets both TSO/TSO6,
or do the following.

> Alternatively, we can add a new features bit which gives the inherent
> features of a device.  That can then be used to derive the actual
> features in use.  That way we won't need to invent a new ethtool
> helper function for this.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt