[PATCH] [RFC] netfilter: don't assume NFPROTO_* are like PF_*

With this patch, NFPROTO_* constants don't have the same values as PF_*
constants.

Benefit: it makes NFPROTO_NUMPROTO smaller and saves space as arrays are
smaller.

Issues: might have missed a conversion. I grepped NF_HOOK, nf_register_hook,
nf_register_hooks, and xt_hook_link. So it is probably fine.

NFPROTO_* constants were introduced by commit 7e9c6e.

Signed-off-by: Alban Crequy <redacted>
Reviewed-by: Javier Martinez Canillas <redacted>
Reviewed-by: Vincent Sanders <redacted>
---
 include/linux/netfilter.h |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 29734be..89afadb 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h

@@ -62,11 +62,11 @@ enum nf_inet_hooks {
 
 enum {
 	NFPROTO_UNSPEC =  0,
-	NFPROTO_IPV4   =  2,
-	NFPROTO_ARP    =  3,
-	NFPROTO_BRIDGE =  7,
-	NFPROTO_IPV6   = 10,
-	NFPROTO_DECNET = 12,
+	NFPROTO_IPV4,
+	NFPROTO_ARP,
+	NFPROTO_BRIDGE,
+	NFPROTO_IPV6,
+	NFPROTO_DECNET,
 	NFPROTO_NUMPROTO,
 };
 

-- 
1.7.2.5

On Monday 2012-05-14 15:58, Alban Crequy wrote:

This must not be changed under any circumstances. It is exported to
and used by userspace. (Except perhaps for NFPROTO_DECNET, which
refers to a quite dead protocol that I think no user parts have ever
used NFPROTO_DECNET.) I would consider it acceptable to change the
value for NFPROTO_DECNET if Pablo joins.

Le Mon, 14 May 2012 17:09:54 +0200 (CEST),
Jan Engelhardt [off-list ref] a écrit :

On Monday 2012-05-14 15:58, Alban Crequy wrote:

quoted

--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h

@@ -62,11 +62,11 @@ enum nf_inet_hooks {

enum {
	NFPROTO_UNSPEC =  0,
-	NFPROTO_IPV4   =  2,
-	NFPROTO_ARP    =  3,
-	NFPROTO_BRIDGE =  7,
-	NFPROTO_IPV6   = 10,
-	NFPROTO_DECNET = 12,
+	NFPROTO_IPV4,
+	NFPROTO_ARP,
+	NFPROTO_BRIDGE,
+	NFPROTO_IPV6,
+	NFPROTO_DECNET,
	NFPROTO_NUMPROTO,
};

This must not be changed under any circumstances. It is exported to
and used by userspace. (Except perhaps for NFPROTO_DECNET, which
refers to a quite dead protocol that I think no user parts have ever
used NFPROTO_DECNET.) I would consider it acceptable to change the
value for NFPROTO_DECNET if Pablo joins.

Thanks for the review. I didn't realize it was exported to and used by
userspace. I would drop this patch then.

Alban

On Mon, May 14, 2012 at 05:09:54PM +0200, Jan Engelhardt wrote:

On Monday 2012-05-14 15:58, Alban Crequy wrote:

quoted

--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h

@@ -62,11 +62,11 @@ enum nf_inet_hooks {

enum {
	NFPROTO_UNSPEC =  0,
-	NFPROTO_IPV4   =  2,
-	NFPROTO_ARP    =  3,
-	NFPROTO_BRIDGE =  7,
-	NFPROTO_IPV6   = 10,
-	NFPROTO_DECNET = 12,
+	NFPROTO_IPV4,
+	NFPROTO_ARP,
+	NFPROTO_BRIDGE,
+	NFPROTO_IPV6,
+	NFPROTO_DECNET,
	NFPROTO_NUMPROTO,
};

This must not be changed under any circumstances. It is exported to
and used by userspace. (Except perhaps for NFPROTO_DECNET, which
refers to a quite dead protocol that I think no user parts have ever
used NFPROTO_DECNET.) I would consider it acceptable to change the
value for NFPROTO_DECNET if Pablo joins.

If there is some remote posibility to break userspace code, I won't
take the patch, sorry.