bridge: netfilter: unroll NF_HOOK helper in bridge input path
Replace NF_HOOK() based invocation of the netfilter hooks with a private
copy of nf_hook_slow().
This copy has one difference: it can return the rx handler value expected
by the stack, i.e. RX_HANDLER_CONSUMED or RX_HANDLER_PASS.
This is needed by the next patch to invoke the ebtables
"broute" table via the standard netfilter hooks rather than the custom
"br_should_route_hook" indirection that is used now.
When the skb is to be "brouted", we must return RX_HANDLER_PASS from the
bridge rx input handler, but there is no way to indicate this via
NF_HOOK(), unless perhaps by some hack such as exposing bridge_cb in the
netfilter core or a percpu flag.
text data bss dec filename
3369 56 0 3425 net/bridge/br_input.o.before
3458 40 0 3498 net/bridge/br_input.o.after
This allows removal of the "br_should_route_hook" in the next patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index e2f93e5..4ac34fb 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -16,6 +16,7 @@
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netfilter_bridge.h>
+#include <net/netfilter/nf_queue.h>
#include <linux/neighbour.h>
#include <net/arp.h>
#include <linux/export.h>
@@ -206,6 +207,55 @@ static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_bu
return 0;
}
+static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
+{
+#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
+ struct nf_hook_entries *e = NULL;
+ struct nf_hook_state state;
+ unsigned int verdict, i;
+ struct net *net;
+ int ret;
+
+ net = dev_net(skb->dev);
+#ifdef HAVE_JUMP_LABEL
+ if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))
+ goto frame_finish;
+#endif
+
+ e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]);
+ if (!e)
+ goto frame_finish;
+
+ nf_hook_state_init(&state, NF_BR_PRE_ROUTING,
+ NFPROTO_BRIDGE, skb->dev, NULL, NULL,
+ net, br_handle_frame_finish);
+
+ for (i = 0; i < e->num_hook_entries; i++) {
+ verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state);
+ switch (verdict & NF_VERDICT_MASK) {
+ case NF_ACCEPT:
+ break;
+ case NF_DROP:
+ kfree_skb(skb);
+ return RX_HANDLER_CONSUMED;
+ case NF_QUEUE:
+ ret = nf_queue(skb, &state, e, i, verdict);
+ if (ret == 1)
+ continue;
+ return RX_HANDLER_CONSUMED;
+ default: /* STOLEN */
+ return RX_HANDLER_CONSUMED;
+ }
+ }
+frame_finish:
+ net = dev_net(skb->dev);
+ br_handle_frame_finish(net, NULL, skb);
+#else
+ br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
+#endif
+ return RX_HANDLER_CONSUMED;
+}
+
/*
* Return NULL if skb is handled
* note: already called with rcu_read_lock
@@ -304,10 +354,7 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
if (ether_addr_equal(p->br->dev->dev_addr, dest))
skb->pkt_type = PACKET_HOST;
- NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
- dev_net(skb->dev), NULL, skb, skb->dev, NULL,
- br_handle_frame_finish);
- break;
+ return nf_hook_bridge_pre(skb, pskb);
default:
drop:
kfree_skb(skb);
