[PATCH net-next 07/12] netfilter: flowtable: move ipv4 and ipv6 xmit path to function

[Pablo Neira Ayuso <pablo@netfilter.org>]

Move the existing ipv4 and ipv6 transmit path to functions in
preparation of the IPv4 over IPv6 and SIT support.

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_flow_table_ip.c | 92 +++++++++++++++++++-------------
 1 file changed, 54 insertions(+), 38 deletions(-)

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 3f417a43bd12..ff45f17f3c4a 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -801,33 +801,17 @@ static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb,
 	return NF_STOLEN;
 }
 
-unsigned int
-nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
-			const struct nf_hook_state *state)
+static int nf_flow_queue_xmit4(struct sk_buff *skb,
+			       struct flow_offload_tuple_rhash *tuplehash,
+			       const struct nf_hook_state *state)
 {
-	struct flow_offload_tuple_rhash *tuplehash;
-	struct nf_flowtable *flow_table = priv;
 	struct flow_offload_tuple *other_tuple;
 	enum flow_offload_tuple_dir dir;
-	struct nf_flowtable_ctx ctx = {
-		.in	= state->in,
-	};
 	struct nf_flow_xmit xmit = {};
 	struct flow_offload *flow;
 	struct neighbour *neigh;
 	struct rtable *rt;
 	__be32 ip_daddr;
-	int ret;
-
-	tuplehash = nf_flow_offload_lookup(&ctx, flow_table, skb);
-	if (!tuplehash)
-		return NF_ACCEPT;
-
-	ret = nf_flow_offload_forward(&ctx, flow_table, tuplehash, skb);
-	if (ret < 0)
-		return NF_DROP;
-	else if (ret == 0)
-		return NF_ACCEPT;
 
 	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
 		rt = dst_rtable(tuplehash->tuple.dst_cache);
@@ -881,6 +865,30 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 
 	return nf_flow_queue_xmit(state->net, skb, &xmit);
 }
+
+unsigned int
+nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
+			const struct nf_hook_state *state)
+{
+	struct flow_offload_tuple_rhash *tuplehash;
+	struct nf_flowtable *flow_table = priv;
+	struct nf_flowtable_ctx ctx = {
+		.in	= state->in,
+	};
+	int ret;
+
+	tuplehash = nf_flow_offload_lookup(&ctx, flow_table, skb);
+	if (!tuplehash)
+		return NF_ACCEPT;
+
+	ret = nf_flow_offload_forward(&ctx, flow_table, tuplehash, skb);
+	if (ret < 0)
+		return NF_DROP;
+	else if (ret == 0)
+		return NF_ACCEPT;
+
+	return nf_flow_queue_xmit4(skb, tuplehash, state);
+}
 EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);
 
 static void nf_flow_nat_ipv6_tcp(struct sk_buff *skb, unsigned int thoff,
@@ -1121,33 +1129,17 @@ nf_flow_offload_ipv6_lookup(struct nf_flowtable_ctx *ctx,
 	return flow_offload_lookup(flow_table, &tuple);
 }
 
-unsigned int
-nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
-			  const struct nf_hook_state *state)
+static int nf_flow_queue_xmit6(struct sk_buff *skb,
+			       struct flow_offload_tuple_rhash *tuplehash,
+			       const struct nf_hook_state *state)
 {
-	struct flow_offload_tuple_rhash *tuplehash;
-	struct nf_flowtable *flow_table = priv;
 	struct flow_offload_tuple *other_tuple;
 	enum flow_offload_tuple_dir dir;
-	struct nf_flowtable_ctx ctx = {
-		.in	= state->in,
-	};
 	struct nf_flow_xmit xmit = {};
 	struct in6_addr *ip6_daddr;
 	struct flow_offload *flow;
 	struct neighbour *neigh;
 	struct rt6_info *rt;
-	int ret;
-
-	tuplehash = nf_flow_offload_ipv6_lookup(&ctx, flow_table, skb);
-	if (tuplehash == NULL)
-		return NF_ACCEPT;
-
-	ret = nf_flow_offload_ipv6_forward(&ctx, flow_table, tuplehash, skb);
-	if (ret < 0)
-		return NF_DROP;
-	else if (ret == 0)
-		return NF_ACCEPT;
 
 	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
 		rt = dst_rt6_info(tuplehash->tuple.dst_cache);
@@ -1202,4 +1194,28 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 
 	return nf_flow_queue_xmit(state->net, skb, &xmit);
 }
+
+unsigned int
+nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
+			  const struct nf_hook_state *state)
+{
+	struct flow_offload_tuple_rhash *tuplehash;
+	struct nf_flowtable *flow_table = priv;
+	struct nf_flowtable_ctx ctx = {
+		.in	= state->in,
+	};
+	int ret;
+
+	tuplehash = nf_flow_offload_ipv6_lookup(&ctx, flow_table, skb);
+	if (!tuplehash)
+		return NF_ACCEPT;
+
+	ret = nf_flow_offload_ipv6_forward(&ctx, flow_table, tuplehash, skb);
+	if (ret < 0)
+		return NF_DROP;
+	else if (ret == 0)
+		return NF_ACCEPT;
+
+	return nf_flow_queue_xmit6(skb, tuplehash, state);
+}
 EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook);
-- 
2.47.3