netfilter: bridge: move br_netfilter out of the core
Jesper reported that br_netfilter always registers the hooks since
this is part of the bridge core. This harms performance for people that
don't need this.
This patch modularizes br_netfilter so it can be rmmod'ed, thus,
the hooks can be unregistered. I think the bridge netfilter should have
been a separated module since the beginning, Patrick agreed on that.
Note that this is breaking compatibility for users that expect that
bridge netfilter is going to be available after explicitly 'modprobe
bridge' or via automatic load through brctl.
However, the damage can be easily undone by modprobing br_netfilter.
The bridge core also spots a message to provide a clue to people that
didn't notice that this has been deprecated.
On top of that, the plan is that nftables will not rely on this software
layer, but integrate the connection tracking into the bridge layer to
enable stateful filtering and NAT, which is was bridge netfilter users
seem to require.
This patch still keeps the fake_dst_ops in the bridge core, since this
is required by when the bridge port is initialized. So we can safely
modprobe/rmmod br_netfilter anytime.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Florian Westphal <fw@strlen.de>
diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h
index fe996d5..c755e49 100644
--- a/include/linux/netfilter_bridge.h
+++ b/include/linux/netfilter_bridge.h
@@ -15,7 +15,7 @@
NF_BR_PRI_LAST = INT_MAX,
};
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
#define BRNF_PKT_TYPE 0x01
#define BRNF_BRIDGED_DNAT 0x02
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 07c9fdd..c4ff43f 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -156,7 +156,7 @@
};
#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
struct nf_bridge_info {
atomic_t use;
unsigned int mask;
@@ -560,7 +560,7 @@
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct nf_conntrack *nfct;
#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
struct nf_bridge_info *nf_bridge;
#endif
@@ -2977,7 +2977,7 @@
atomic_inc(&nfct->use);
}
#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
{
if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
@@ -2995,7 +2995,7 @@
nf_conntrack_put(skb->nfct);
skb->nfct = NULL;
#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
nf_bridge_put(skb->nf_bridge);
skb->nf_bridge = NULL;
#endif
@@ -3016,7 +3016,7 @@
nf_conntrack_get(src->nfct);
dst->nfctinfo = src->nfctinfo;
#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
dst->nf_bridge = src->nf_bridge;
nf_bridge_get(src->nf_bridge);
#endif
@@ -3030,7 +3030,7 @@
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
nf_conntrack_put(dst->nfct);
#endif
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
nf_bridge_put(dst->nf_bridge);
#endif
__nf_copy(dst, src);
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 47f4254..f60558d 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -373,7 +373,7 @@
return 0;
}
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
{
unsigned int seq, hh_alen;
diff --git a/include/net/netfilter/ipv4/nf_reject.h b/include/net/netfilter/ipv4/nf_reject.h
index 931fbf8..f713b5a 100644
--- a/include/net/netfilter/ipv4/nf_reject.h
+++ b/include/net/netfilter/ipv4/nf_reject.h
@@ -98,7 +98,7 @@
nf_ct_attach(nskb, oldskb);
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
/* If we use ip_local_out for bridged traffic, the MAC source on
* the RST will be ours, instead of the destination's. This confuses
* some routers/firewalls, and they drop the packet. So we need to
diff --git a/include/net/netfilter/ipv6/nf_reject.h b/include/net/netfilter/ipv6/nf_reject.h
index 710d17e..7a10cfc 100644
--- a/include/net/netfilter/ipv6/nf_reject.h
+++ b/include/net/netfilter/ipv6/nf_reject.h
@@ -147,7 +147,7 @@
nf_ct_attach(nskb, oldskb);
-#ifdef CONFIG_BRIDGE_NETFILTER
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
/* If we use ip6_local_out for bridged traffic, the MAC source on
* the RST will be ours, instead of the destination's. This confuses
* some routers/firewalls, and they drop the packet. So we need to