netfilter: Introduce NFPROTO_* constants

The netfilter subsystem only supports a handful of protocols (much
less than PF_*) and even non-PF protocols like ARP and
pseudo-protocols like PF_BRIDGE. By creating NFPROTO_*, we can earn a
few memory savings on arrays that previously were always PF_MAX-sized
and keep the pseudo-protocols to ourselves.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 12 insertions, 2 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 8c83d2e23bde..bf3afb0844f7 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -52,6 +52,16 @@ enum nf_inet_hooks {
         NF_INET_NUMHOOKS
 };
 
+enum {
+        NFPROTO_UNSPEC =  0,
+        NFPROTO_IPV4   =  2,
+        NFPROTO_ARP    =  3,
+        NFPROTO_BRIDGE =  7,
+        NFPROTO_IPV6   = 10,
+        NFPROTO_DECNET = 12,
+        NFPROTO_NUMPROTO,
+};
+
 union nf_inet_addr {
         __u32           all[4];
         __be32          ip;
@@ -138,7 +148,7 @@ extern struct ctl_path nf_net_netfilter_sysctl_path[];
 extern struct ctl_path nf_net_ipv4_netfilter_sysctl_path[];
 #endif /* CONFIG_SYSCTL */
 
-extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
+extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
 
 int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
                  struct net_device *indev, struct net_device *outdev,
@@ -247,7 +257,7 @@ struct nf_afinfo {
         int             route_key_size;
 };
 
-extern const struct nf_afinfo *nf_afinfo[NPROTO];
+extern const struct nf_afinfo *nf_afinfo[NFPROTO_NUMPROTO];
 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
 {
         return rcu_dereference(nf_afinfo[family]);