[PATCH net-next v2] ipv6: remove old conditions on flow label sharing

[PATCH net-next v2] ipv6: remove old conditions on flow label sharing

[Florent Fourcot]

The code of flow label in Linux Kernel follows
the rules of RFC 1809 (an informational one) for
conditions on flow label sharing. There rules are
not in the last proposed standard for flow label
(RFC 6437), or in the previous one (RFC 3697).

Since this code does not follow any current or
old standard, we can remove it.

With this removal, the ipv6_opt_cmp function is
now a dead code and it can be removed too.

Changelog to v1:
 * add justification for the change
 * remove the condition on IPv6 options

Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
---
 net/ipv6/ip6_flowlabel.c | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 46e8843..ff20f5a 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -476,23 +476,6 @@ static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 	return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 }

-static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
-{
-	if (o1 == o2)
-		return false;
-	if (o1 == NULL || o2 == NULL)
-		return true;
-	if (o1->opt_nflen != o2->opt_nflen)
-		return true;
-	if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
-		return true;
-	if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
-		return true;
-	if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
-		return true;
-	return false;
-}
-
 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 		struct ip6_flowlabel *fl)
 {
@@ -603,11 +586,6 @@ recheck:
 				     uid_eq(fl1->owner.uid, fl->owner.uid)))
 					goto release;

-				err = -EINVAL;
-				if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
-				    ipv6_opt_cmp(fl1->opt, fl->opt))
-					goto release;
-
 				err = -ENOMEM;
 				if (sfl1 == NULL)
 					goto release;
--
1.8.4.rc3

Re: [PATCH net-next v2] ipv6: remove old conditions on flow label sharing

[Hannes Frederic Sowa]

On Sat, Nov 02, 2013 at 02:55:07PM +0100, Florent Fourcot wrote:
> The code of flow label in Linux Kernel follows
> the rules of RFC 1809 (an informational one) for
> conditions on flow label sharing. There rules are
> not in the last proposed standard for flow label
> (RFC 6437), or in the previous one (RFC 3697).
> 
> Since this code does not follow any current or
> old standard, we can remove it.
> 
> With this removal, the ipv6_opt_cmp function is
> now a dead code and it can be removed too.
> 
> Changelog to v1:
>  * add justification for the change
>  * remove the condition on IPv6 options
> 
> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>

Yup, makes sense.

Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Thanks,

  Hannes

Re: [PATCH net-next v2] ipv6: remove old conditions on flow label sharing

[David Miller]

From: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Date: Sat,  2 Nov 2013 14:55:07 +0100

> The code of flow label in Linux Kernel follows
> the rules of RFC 1809 (an informational one) for
> conditions on flow label sharing. There rules are
> not in the last proposed standard for flow label
> (RFC 6437), or in the previous one (RFC 3697).
> 
> Since this code does not follow any current or
> old standard, we can remove it.
> 
> With this removal, the ipv6_opt_cmp function is
> now a dead code and it can be removed too.
> 
> Changelog to v1:
>  * add justification for the change
>  * remove the condition on IPv6 options
> 
> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>

Applied, but I had to also remove ipv6_hdr_cmp() as that became unused
as well.

Thanks.